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Software Engineering Questions

2011-05-10T18:13:00.001+05:30

1. How might a project policy that requires all programming staff to produce 50 lines of documentation per 1000 LOC prove inappropriate or counter-productive?
Ans : Provide 5 examples to support your position and limit your answer to 500 words or less.
This policy could reward inappropriate behaviour such as
1. a programmer that is very careful to produce self-documenting code and thus may feel that he/she does not need to add extra documentation may be discouraged from continuing to produce self-documenting code.
2. mandating a specific number of documentation lines per 1000 LOC does not take into account that there are differences in the amount of documentation needed for different types of code - very complex algorithms may need more and standard business type apps may take less and rewarding them in the same way does not impress upon the programmers when documentation is appropriate and necessary.
3. mandating the amount and not the quality does not reward the programmer that produces clear, concise comments as opposed to the programmer that produces lots of rambling, confusing documentation.
4. to connect the code to the requirements, specification and design documents, the comments may in fact be very terse since they just reference these documents and thus once again this appropriate behaviour may be inadvertently discouraged.
5. this policy does not address the case where programmers are extending classes or modifying existing codes - there may not be a clear way to count either the real LOC or the appropriate number of comments since these are both influenced by previous work. If the current programmer is punished for the inappropriate behaviour of others this will taint the programmer's view of extending or using other's code.

2. Compute the function point count for the system which is described in the following informal requirements statement. Clearly state all assumptions that you make.
Ans : The system processes various commands from an operator of a chemical plant. These commands include:
• calculate and display the average temperature of a specific reactor over a 24-hour period
• calculate and display the average pressure in a specific reactor over a 24-hour period
• calculate and display a summary of the average temperatures and pressures in a specific reactor over a given time period (where the time period is greater than 1 day)
The operator can also send the results to an electronic bulletin board.

3. Develop 4 different definitions for LOC that are most appropriate for the following purposes:
1. maintainability
2. testability
3. system efficiency
4. programmer efficiency
Justify your definitions and test them out on the code you and your partner produced for any of the pair programming exercises.
Ans : • maintainability
o For maintainability, one should reward behaviour that produces well-documented code that is neither too terse or too verbose. To this end, LOC should be divided into lines of documentation, total number of LOC, and lines of executable code. If there are many lines of executable code versus total LOC then this is probably complex code that should be very well documented and thus the number of documentation lines can be evaluated with this in mind.
• testability
o For testability, the most important LOC feature is the number of executable lines since this will give you an idea of the complexity of the code and thus the quantity of testing that will be needed. If number of executable lines can be further divided into number of "control" lines (if-then-else, switch, etc) then this measure of complexity and need for tests will be further enhanced.
• system efficiency
o For system efficiency, the most important LOC features are lines of execution versus lines of non-execution that are not comment lines. A large number of non-execution lines may be an indication of lots of memory allocations - this might be a sign of possible system efficiency problems - not guaranteed to be but worth a look.
• programmer efficiency
o For programmer efficiency, the LOC features to compare would be the ratio between executable lines, non-executable lines and comment lines. This should be in balance so that one does not dominant the others. Once again this is just a way to flag if a programmer has a distinctive propensity to be too verbose or too terse.

4. Compare the measurement of program size in the case of traditional procedural programming languages and in the case of object-oriented languages. Construct your answer in the following way:
• briefly describe how size is measured in procedural language programs
• briefly describe how size is measured in object-oriented language programs
• describe the similarities
• describe the differences
Limit your answer to 500 words.

5. Develop a project policy statement that uses lines of code and the quality metrics of your choice (i.e. equations that relate LOC to elements of quality such as productivity, maintainability, etc.) to motivate and reward team members.
Ans : Provide 4 examples to support your policy decisions and limit your answer to 100 words or less.
Policy: To produce extensible/reusable code, programmers will be advised to produce code that has the following properties:
• each logical segment of code (e.g. class, method, etc) will have a ratio of lines of documentation to lines of code of at least 1:10
• all logical segment of code should be of a similar size (+- 20%) with regards LOC
This policy will have the following effects:
1. encourage documentation but not too much documentation
2. encourage programmers to consider the size of their classes and methods and thus to review their design choices and code properties such as high cohesion and low coupling
3. since this policy will probably result in code that is highly compartmentalized and well designed, it will be easier to reuse
4. since each module will be appropriately documented this should also make reuse and extending more likely

6. Assume that you're the manager of a small project. What baselines would you define for the project and how would you control them?
Ans : A baseline is a software configuration management concept that helps us to control change without seriously impeding justifiable change. The baselines that I will define for the project are as under:
• Schedule baseline
• Cost baseline
• Scope baseline
• Development baseline
• Source code
• Test cases
• Design specification
• System specification
• Software requirements
As a project manager, I will ensure that all the baselines are being met accordingly and the software project is proceeding as desired. Software schedule will be monitored throughout the software development, and in case of any deficiencies, appropriate solution will be figured out. Cost is also a baseline for project. It can only be met in case the software requirements are easily understood and are complete. Source code needs also be checked through the development process and the bugs that are found will be fixed at appropriate time in order to deliver good quality product to end users.

2. What is the difference between an SCM audit and a formal technical review?
Answer.
1st version of the answer:
SCM Audit:
A software configuration audit complements the formal technical review by assessing aconfiguration object for characteristics that are generally not considered during review.
Formal Technical Review:
The formal technical review focuses on the technical correctness of the configuration object thathas been modified. The reviewers assess the SCI to determine consistency with other SCIs,omissions, or potential side effects. A formal technical review is the most effective filter from aquality assurance standpoint. Conducted by software engineers for software engineers, the FTRis an effective means for improving software quality.
No, the functions of SCM Audit and Formal Technical Review cannot be folded into one reviewbecause of the fact.
Formal Technical Reviews are used for improving software quality, whereas softwareconfiguration management audit is usually used to answer the questions that are indirectlyrelated to software to achieve the desired quality. For example, we can perform formal technicalreviews for coding, testing, debugging, etc., as these are directly related to the quality of thesoftware, however, for SCM Audit, we will answer the questions which are not directly related tosoftware quality rather indirectly. Some questions could be...
• Has the change specified in the ECO been made?
• Have any additional modifications beenincorporated?
• Has a formal technical review been conducted to assess technical correctness?
• Has the software process been followed and have software engineering standards beenproperly applied?
• Has the change been "highlighted" in the SCI?
• Have the change date and change authorbeen specified?
• Do the attributes of the configuration object reflect the change?
• Have SCM procedures for noting the change, recording it, and reporting it beenfollowed?
• Have all related SCIs been properly updated?
• Besides above, in some cases questions are asked as part of a formal technical review. However,when SCM is a formal activity, the SCM audit is conducted separately by the quality assurancegroup.

Computer Network Questions and Answers

2011-04-01T19:02:00.000+05:30

Q-1 What are the goals in mind of IEEE 802 committee?
Ans: IEEE 802 committee has few goals in mind, namely
–To promote compatibility
–Implementation with minimum efforts
–Accommodate diverse applications

Q-2. List the functions performed by the physical layer of 802.3 standard?
Ans. Functions of physical layer are:
i) Data encoding/decoding (To facilitate synchronization and efficient transfer of signal through the medium).
ii) Collision detection (It detects at the transmit side)
iii) Carrier sensing (Channel access senses a carrier on the channel at both the transmit and receive sides)
iv) Transmit/receive the packets (Frame transmitted to all stations connected to the channel)
v) Topology and medium used (Mediums are co-axial cable, twisted pair and fiber optic cable)

Q-3. Why do you require a limit on the minimum size of Ethernet frame?
Ans. To detect collision, it is essential that a sender continue sending a frame and at the same time receives another frame sent by another station. Considering maximum delay with five Ethernet segments in cascade, the size of frame has been found to be 64 bytes such that the above condition is satisfied.

Q-4. What are the different types of cabling supported by Ethernet standard?
Ans. Types of cabling are:
i) 10 BASE 5 - Maximum cable length is 500 meters using 4” diameter coaxial cable.
ii) 10 BASE 2 - Maximum cable length is 185 meters using 0.25” diameter CATV cable.
iii) 10 BASE T - Maximum cable length is 100 meters using twisted-pair cable (CAT-3 UTP).
iv) 10 BASE FL - Maximum cable length is 2 Km using multimode fiber optic cable (125/62.5 micrometer).

Q-5. Explain the basic difference between IEEE 802.3 and switched Ethernet, as far as implementation is concerned.
Ans: In Ethernet (IEEE 802.3) the topology, though physically is start but logically is BUS. i.e. the collision domain of all the nodes in a LAN is common. In this situation only one frame can send the frame, if more than one station sends the frame, there is a collision.
In Switched Ethernet, this collision domain is separated. Hub is replaced by a switch, a device that can recognize the destination address and can route the frame to the port to which the destination station is connected, the rest of the media is not involved in the transmission process. The switch can receive another frame from another station at the same time and can route this frame to its own final destination.

Q-6. Explain the two techniques for implementing Ethernet switches.
Ans: There are two techniques used in the implementation of Ethernet switches: store-and-forward and cut-through. In the first case, the entire frame is captured at the incoming port, stored in the switch’s memory, and after an address lookup to determine the LAN destination port, forwarded to the appropriate port. The lookup table is automatically built up. On the other hand, a cut-through switch begins to transmit the frame to the destination port as soon as it decodes the destination address from the frame header.
Store-and-forward approach provides a greater level of error detection because damaged frames are not forwarded to the destination port. But, it introduces longer delay of about 1.2 msec for forwarding a frame and suffers from the chance of loosing data due to reliance on buffer memory. The cut-through switches, on the other hand, has reduced latency but has higher switch cost.

Q-7. What are the different categories of Fast Ethernet?
Ans: IEEE has designed two categories of Fast Ethernet: 100Base-X and 100Base-T4. 100Base-X uses two cables between hub and the station while 100Base-T4 uses four. 100-Base-X itself is divided into two: 100Base-TX and 100base-FX.
* 100 BASE-T4: This option is designed to avoid overwriting. It is used for half-duplex communication using four wire-pairs of the existing category 3 UTP cable, which is already available for telephone services in homes/offices. Two of four pairs are bi-directional; other two are unidirectional. This means that there are 3 pairs to be used for carrying data, in each direction (2 bi-directional and 1 uni-directional). Because 100Mbps data cannot be handled by voice-grade UTP, this specification splits the 100 Mbps flow into three 33.66Mbps flow.
* 100 BASE TX: This option uses two category 5 UTP or two shielded (STP) cable to connect a station to hub. One pair is used to carry frames from the hub to the station and other to carry frames from station to hub. Encoding is 4B/5B to handle 100 Mbps; signaling is NRZ-I. The distance between station and hub should be less than 100 meters.
* 100 BASE FX: This option uses two Fiber optic cables, one carry frames from station to hub and other from hub to station. The encoding is 4B/5B and signaling in NRZ-I. the distance between station and hub should be less than 2000 meters.

Q-8. What are the Objectives of The Gigabit Ethernet Alliance?
Ans: The objectives of the alliance are:
• supporting extension of existing Ethernet and Fast Ethernet technology in response to demand for higher network bandwidth.
• developing technical proposals for the inclusion in the standard
• establishment of inter-operability test procedures and processes

Q-9. Explain GMII (Gigabit Media Independent Interface) in brief.
Ans: The GMII is the interface between the MAC layer and the Physical layer. It allows any physical layer to be used with the MAC layer. It is an extension of the MII (Media Independent Interface) used in Fast Ethernet. It uses the same management interface as MII. It supports 10, 100 and 1000 Mbps data rates. It provides separate 8-bit wide receive and transmit data paths, so it can support both full-duplex as well as half-duplex operation.
The GMII provides 2 media status signals: one indicates presence of the carrier, and the other indicates absence of collision. With the GMII, it is possible to connect various
media types such as shielded and unshielded twisted pair, and single-mode and multi mode optical fiber, while using the same MAC controller. It has three sub-layers namely: PCS (Physical Coding Sublayer), PMA (Physical Medium Attachment) and PMD (Physical Medium Dependent)

Computer Network Questions and Answers

2011-03-23T13:25:00.000+05:30

1. The IP datagram for a TCP ACK message is 40 bytes long: It contains 20 bytes of TCP header and 20 bytes of IP header. Assume that this ACK is traversing an ATM network that uses AAL5 to encapsulate IP packets. How many ATM layer packets will it take to carry the ACK for each of AAL layer?
a. AAL5
b. AAL3/4
ANS
a)) The length of the AAL5 CS-PDU into which the ACK is encapsulated is exactly 48 bytes, and this fits into a single ATM cell.
b)) When AAL3/4 is used the CS-PDU is again 48 bytes, but now the per-cell payload is only 44 bytes and two cells are necessary.

2. Suppose there are N stations on a LAN that has capacity (transmission rate) C. All packets have a fixed length L and the end-to-end propagation delay of the channel is P. If only one station ever has a message to send (i.e., the other N-1 stations generate no traffic). What is the maximum possible throughput seen by this single node under each of the protocols:
a. CSMA
Assuming that the station senses the channel immediately after finishing its transmission, and finding it idle, sends another packet, the throughput is C. Note that this ignores the overhead time needed to do channel sensing.

b. Slotted Aloha
Assuming the station always has data to send, it will always to do under slotted Aloha, so the throughput would be C.

c. Token Passing
After sending a message, a station gives up the token. The token circulates around the ring (taking time P). Assuming that L is the amount of time needed to transmit a message, the throughput is thus (L/(L+PC))*C.

3. Consider sending a 1500-byte datagram into a link that has an MTU of 500 bytes. Suppose the original datagram is stamped with the identification number 1. Assume that IPv4 is used.
a. Where does fragmentation happen? Where are the fragments reassembled?
Fragmentation happens in the router preceding the link with the small MTU. The fragments are reassembled in the end system.

b. How many fragments are generated?
The maximum size of the data field in each fragment = 480 (because there are 20 bytes IP header). Thus the number of required fragments= 1500-20/480 = 4

c. What are the values of the fragmentation-related fields in the generated IP datagram(s)?
Each fragment will have an identical identification number. Each fragment except the last one will be of size 500 bytes (including the IP header). The last datagram will be of size 60 bytes (including the IP header). The offsets of the 4 fragments will be 0, 60, 120, 180. Each of the first 3 fragments will have flag=1; the last fragment will have flag=0.

d. What changes if IPv6 were used?
The router preceding the link with the small MTU will drop the packet and send an ICMP error message “Packet Too Big” back to the source. The source is responsible for adjusting the packet size.

4. Consider building a CSMA/CD network running at 1 Gbps over a 1-km cable with no repeaters. The signal speed in the cable is 200,000 km/sec. What is the minimum frame size?
ANS
For a 1-km cable, the one-way propagation time is 5 μsec, so 2τ = 10 μsec. To make CSMA/CD work, it must be impossible to transmit an entire frame in this interval. At 1 Gbps, all frames shorter than 10,000 bits can be completely transmitted in under 10 μsec, so the minimum frame is 10,000 bits or 1250 bytes

5. In the CSMA/CD protocol, what condition on the transmission delay Ttrans and the propagation delay Tprop has to be satisfied to guarantee that a node always detects a collision?
ANS Ttrans>2Tprop

6. At low load, consider the delay of pure ALOHA versus slotted ALOHA. Which one is less? Explain your answer.
ANSWith pure ALOHA, transmission can start instantly. At low load, no collisions are expected so the transmission is likely to be successful. With slotted ALOHA, it has to wait for the next slot. This introduces half a slot time of delay.

Operating System Questions

2011-03-22T09:44:00.000+05:30

1. Define operating system (MU AP-96)
An operating system is a set of program that controls, co-ordinates and supervises the activities of the computer hardware and software.

2. What is the role of an os?

An OS acts as an interface between the user and the computer. It acts as The manager of the resources of the computer.

3. Write the functions of an OS(BU Ap-97)

(i) Memory Management.
(ii) Processor management.
(iii) Interrupt Handling.
(iv) Accounting.
(v) Automatic job sequencing.
(vi) Management and control of I/O devices

4. What is the need for an OS?
A medium is needed to communicate between the user and the m/c. An OS acts as a medium of interface

5. What are the characteristics of an OS(MSU Ap-96)
(i) User friendly .
(ii) Keep track of the status of eaCH RESOURCE.
(iii) Allows sharing of resources(H/W and S/W).
(iv) Provides adequate security.
(v) Protection.

6. What is a process?
A process is basically a program in execution. It is the unit of work in a Modern operating system.

7. What is meant by a process state?
When a process executes, it changes, its status. This is known as process's State.

8. What are the various process states ?

The various process states are
(i) new
(ii) ready
(iii) running
(iv) suspended
(v) terminated

9. How does a process differ from a job?(BDU Ap-96).
A process is an active entity with a program counter specifying the next instructions to execute and a set to associated resources, whereas a batch System executes jobs.(which is a collection of processes).

10. Differentiate program and a process?
A process is a program in execution(ie) A program is a passive entity, Where as a process is an active entity.

11. What is process control Block?
Each process is represented in the operating system by a process control Block(PCB) also called a task control block.

12. What is the function of a process control block?
A (PCB) contains many pieces of information associated with a specific Process. It serves as the repository for any information that may vary From process to process.

13. What are the information contained in a PCB?
A PCB contains pieces of information associated with a specific process, Namely

(i) process state
(ii) program counter
(iii) CPU register
(iv) CPU scheduling information
(v) Memory management information
(vi) Accounting information
(vii) I/O status information

14. What are the operations on process?
(i) create a process
(ii) destroy a process
(iii) suspend a process
(iv) resume a process
(v) change the priority of a process
(vi) block a process
(vii) wakeup a process
(viii) dispatch a process
(ix) enable a process to communicate with another

15. What are the operation involved in creating a process?
(i) name the process
(ii) insert it in the system’s known processes list(or) process table.
(iii) Determine the process’s initial priority
(iv) Create the process control block
(v) Allocate the process’s initial resource.

16. What is the nucleus or kernel of an operating system?

Kernel is the part of the OS which directly makes interface with the Hardware system.

17. What are the main functions of the kernel?

To provide mechanism for
(i) creation and deletion of processes
(ii) inter process communication
(iii) synchronization of processes.

18. What are the components of an OS?
OS which is a collection of programs are of 2 types
(i) control program
(ii) supervisory program

19. What is multi programming?
The ability of keeping several jobs in the memory at one time, where The cpu is switched back and forth among them is called as Multi programming

20. What is the use of Multi Programming ?
Multi programming helps to increase CPU utilization, and to decrease the total time needed to execute the jobs.

21. Illustrate the factors that usually determine the degree of Multi Programming
(MSU: Nov-96)
(i) The number of Programs residing in Primary memory.
(ii) Passing of the control of the CPU rapidly between these programs.
(iii) Protection of user process from one another.

Computer Network Questions and Answers

2010-12-16T10:41:00.001+05:30

1. Why is it important for protocols configured on top of the Ethernet to have a length field in their header, indicating how long the message is?
Ans: It is important to indicate the message size because of the following reasons:
 There can be padded data inside the message,
 In case of collision only part of data is received, so it can checked by the message length field, otherwise, it won't be known.
 The Ethernet frame size isn't fixed. It can hold up to 1500 bytes but it can vary from network to network.

2. What kinds of problems can arise when two hosts on the same Ethernet share the same hardware address? Describe what happens and why that behavior is a problem.
Ans : 1. Hosts are using hardware address to filter whether the packet is for them or not. So, they can discard the packets which do not belong to them. However, if the same hardware address is shared with other host, it is likely to receive wrong packets which can harm the host.
2. On the same Ethernet line, hosts keep dynamic ARP table to match Internet address and physical address (MAC address), but if they see two different IP addresses having same MAC address. It is hard to tell what happens for this.
3. If hosts share the switch on the Ethernet line, the switch will get confused to update the address table. It will continuously change the address table, so it can lead to unstable state.

3. The 1982 Ethernet specification allowed between any two stations up to 1500 m of coaxial cable, 1000 m of other point-to-point link cable, and two repeaters. Each station or repeater connects to the coaxial cable via up to 50 m of “drop cable.” Typical delays associated with each device are given in Table below (where c = speed of light in a vacuum = 3×108 m/s). What is the worst-case round-trip propagation delay, measured in bits, due to the sources listed? (This list is not complete; other sources of delay include sense time and signal rise time.)

Item Delay
Coaxial cable propagation speed .77c
Link/drop cable propagation speed .65c
Repeaters approximately 0.6 μs each
Transceivers approximately 0.2 μs each
Typical delays associated with various devices
One-way delays:
Coax: 1500m 6.49 3 s
link: 1000m 5.13 3 s
repeaters two 1.20 3 s
transceivers six (two for 1.20 3 s
each repeater,
one for each
station)

drop cable 6 , 50m 1.54 3 s
Total: 15.56 3 s
The roundtrip delay is thus about 31.1 3 s, or 311 bits. The “official” total is 464 bits, which when extended by 48 bits of jam signal exactly accounts for the 512-bit minimum packet size.
The 1982 Digital-Intel-Xerox specification presents a delay budget (page 62 of that document) that totals 463.8 bit-times, leaving 20 nanoseconds for unforeseen contingencies.

4. Coaxial cable Ethernet was limited to a maximum of 500 m between repeaters, which regenerate the signal to 100% of its original amplitude. Along one 500-m segment, the signal could decay to no less than 14% of its original value (8.5 dB). Along 1500 m, then, the decay might be (0.14)3 = 0.3%. Such a signal, even along 2500 m, is still strong enough to be read; why then are repeaters required every 500 m?
Ans>>A station must not only detect a remote signal, but for collision detection it must detect a remote signal while it itself is transmitting. This requires much higher remote-signal intensity.

5. Suppose the round-trip propagation delay for Ethernet is 46.4 μs. This yields a minimum packet size of 512 bits (464 bits corresponding to propagation delay + 48 bits of jam signal).
(a) What happens to the minimum packet size if the delay time is held constant, and the signaling rate rises to 100 Mbps?
(b) What are the drawbacks to so large a minimum packet size?
(c) If compatibility were not an issue, how might the specifications be written so as to permit a smaller minimum packet size?
Ans>>(a) Assuming 48 bits of jam signal was still used, the minimum packet size would be 4640+48 bits = 586 bytes.
(b) This packet size is considerably larger than many higher-level packet sizes, resulting in considerable wasted bandwidth.
(c) The minimum packet size could be smaller if maximum collision domain diameter were reduced, and if sundry other tolerances were tightened up.

6. A group of N stations share a 56-kbps pure ALOHA channel. Each station outputs a 1000-bit frame on an average of once every 100 sec, even if the previous one has not yet been sent (e.g., the stations can buffer outgoing frames). What is the maximum value of N?
ANS>>with pure ALOHA the usable bandwidth is 0.184 × 56 kbps = 10.3 kbps.Each station requires 10 bps, so N = 10300/10 = 1030 stations

7. Consider the delay of pure ALOHA versus slotted ALOHA at low load. Which one is less? Explain your answer.
ANS>>With pure ALOHA, transmission can start instantly. At low load, no collisions are expected so the transmission is likely to be successful. With slotted ALOHA, it has to wait for the next slot. This introduces half a slot time of delay.

8. Ten thousand airline reservation stations are competing for the use of a single slotted ALOHA channel. The average station makes 18 requests/hour. A slot is 125 μsec. What is the approximate total channel load?
ANS>>Each terminal makes one request every 200 sec, for a total load of 50 requests/sec. Hence G = 50/8000 = 1/160.

9. A large population of ALOHA users manages to generate 50 requests/sec, including both originals and retransmissions. Time is slotted in units of 40 msec.
a. What is the chance of success on the first attempt?
b. What is the probability of exactly k collisions and then a success?
c. What is the expected number of transmission attempts needed?
ANS>> (a) With G = 2 the Poisson law gives a probability of e −2.
(b) (1 − e −G)ke −G = 0.135 × 0.865k .
(c) The expected number of transmissions is eG = 7.4.

10. Measurements of a slotted ALOHA channel with an infinite number of users show that 10 percent of the slots are idle.
a. What is the channel load, G?
b. What is the throughput?
c. Is the channel underloaded or overloaded?
ANS>> (a) From the Poisson law again, P0 = e −G, so G = −lnP0 = −ln 0.1 = 2.3.
(b) Using S = Ge−G with G = 2.3 and e −G = 0.1, S = 0.23.
(c) Whenever G > 1 the channel is overloaded, so it is overloaded.

11. In an infinite-population slotted ALOHA system, the mean number of slots a station waits between a collision and its retransmission is 4. Plot the delay versus throughput curve for this system.
ANS>>The number of transmissions is E = eG. The E events are separated by E – 1 intervals of four slots each, so the delay is 4(eG − 1). The throughput is given by S = Ge−G. Thus, we have two parametric equations, one for delay and one for throughput, both in terms of G. For each G value it is possible to find the corresponding delay and throughput, yielding one point on the curve.

12. 1-km-long, 10-Mbps CSMA/CD LAN (not 802.3) has a propagation speed of 200 m/μsec. Repeaters are not allowed in this system. Data frames are 256 bits long, including 32 bits of header, checksum, and other overhead. The first bit slot after a successful transmission is reserved for the receiver to capture the channel in order to send a 32-bit acknowledgement frame. What is the effective data rate, excluding overhead, assuming that there are no collisions?
ANS>> The round-trip propagation time of the cable is 10µsec. A complete transmission has six phases: transmitter seizes cable (10µsec) transmit data (25.6µsec) Delay for last bit to get to the end (5.0 µsec) receiver seizes cable (10µsec) acknowledgement sent (3.2 µsec) Delay for last bit to get to the end (5.0 µsec) the sum of these is 58.8 µsec. In this period, 224 data bits are sent, for a rate of about 3.8 Mbps.

13. Consider building a CSMA/CD network running at 1 Gbps over a 1-km cable with no repeaters. The signal speed in the cable is 200,000 km/sec. What is the minimum frame size?
ANS>> For a 1-km cable, the one-way propagation time is 5 μsec, so 2τ = 10 μsec. To make CSMA/CD work, it must be impossible to transmit an entire frame in this interval. At 1 Gbps, all frames shorter than 10,000 bits can be completely transmitted in under 10 μsec, so the minimum frame is 10,000 bits or 1250 bytes.

14. An IP packet to be transmitted by Ethernet is 60 bytes long, including all its headers. If LLC is not in use, is padding needed in the Ethernet frame, and if so, how many bytes?
ANS>>The minimum Ethernet frame is 64 bytes, including both addresses in the Ethernet frame header, the type/length field, and the checksum. Since the header fields occupy 18 bytes and the packet is 60 bytes, the total frame size is 78 bytes, which exceeds the 64-byte minimum. Therefore, no padding is used.

15. Ethernet frames must be at least 64 bytes long to ensure that the transmitter is still going in the event of a collision at the far end of the cable. Fast Ethernet has the same 64-byte minimum frame size but can get the bits out ten times faster. How is it possible to maintain the same minimum frame size?
ANS>>The maximum wire length in fast Ethernet is 1/10 as long as in Ethernet.

16. Some books quote the maximum size of an Ethernet frame as 1518 bytes instead of 1500 bytes. Are they wrong? Explain your answer.
ANS>>The payload is 1500 bytes, but when the destination address, source address, type/length, and checksum fields are counted too, the total is indeed 1518.

17. Recall that with the CSMA/CD protocol, the adapter waits K*512 bit times after a collision, where K is drawn randomly. For K=100, how long does the adapter wait until returning to Step 2 for a 10 Mbps Ethernet? For a 100 Mbps Ethernet?
ANS>> Wait for 51,200 bit times. For 10 Mbps, this wait is

For 100 Mbps, the wait is 512 μ sec.

18. Suppose nodes A and B are on the same 10 Mbps Ethernet segment, and the propagation delay between the two nodes is 225 bit times. Suppose node A begins transmitting a frame, and before it finishes station B begins transmitting a frame. Can A finish transmitting before it detects that B has transmitted? Why or why not? If the answer is yes, then A incorrectly believes that its frame was successfully transmitted without a collision.
Hint: Suppose at time t=0 bit times, A begins transmitting a frame. In the worst case, A transmits a minimum size frame of 512+64(prembale) bit times. So A would finish transmitting the frame at t=512+64 bit times. Thus the answer is no if B's signal reaches A before bit time t=512+64 bits. In the worst case, when does B's signal reach A?

ANS>> At t = 0 A transmits. At t = 576 , A would finish transmitting. In the worst case, B begins transmitting at time t = 224 . At time t = 224 + 225 = 449 B 's first bit arrives at A . Because 449 < 576 , A aborts before completing the transmission of the packet, as it is supposed to do. Thus A cannot finish transmitting before it detects that B transmitted. This implies that if A does not detect the presence of a host, then no other host begins transmitting while A is transmitting. 19. Suppose nodes A and B are on the same 10 Mbps Ethernet segment, and the propagation delay between the two nodes is 225 bit times. Suppose A and B send frames at the same time, the frames collide, and then A and B choose different values of K in the CSMA/CD algorithm. Assuming no other nodes are active, can the retransmissions from A and B collide? For our purposes, it suffices to work out the following example. Suppose A and B begin transmission at t=0 bit times. They both detect collisions at t=225 bit times. They finish transmitting jam signal at t= 225+48= 273 bit times. Suppose KA=0 and KB=1. At what time does B schedule its retransmission? At what time does A begin transmission? (Note, the nodes must wait for an idle channel after returning to Step 2-- see protocol.) At what time does A's signal reach B? Does B refrain from transmitting at its scheduled time?

Time Event
0 A and B begin transmission
225 A and B detect collision
273 A and B finish transmitting jam signal
273+225=498 B 's last bit arrives at A ;A detects an idle channel
498+96=594 A starts transmitting
273+512=785 B returns to Step2
B must sense idle channel for 96 bit times before it transmits
785+96=881 B starts transmitting
594+225=819 A’s transmission reaches B
Because A 's retransmission reaches B before B 's scheduled retransmission time, B refrains from transmitting while A retransmits. Thus A and B do not collide. Thus the factor 512 appearing in the exponential backoff algorithm is sufficiently large.

20. Consider a 100Mbps 100-BT Ethernet. In order to have an efficiency of .50, what should be the maximum distance between a node and the hub? Assume a frame length of 64 bytes and that there are no repeaters. Does this maximum distance also ensure that a transmitting node A will be able to detect whether any other node transmitted while A was transmitting? Why or why not? How does your maximum distance compare to the actual 100 Mbps standard?
Ans>>We want 1/(1+ 5a) = .5 or, equivalently, prop trans a = .2 = t / t . t = d /(1.8 ×108 ) prop m/sec and = (576 trans t bits ) /(108 bits/sec ) = 5.76μ sec. Solving for d we obtain d = 265 meters. For the 100 Mbps Ethernet standard, the maximum distance between two hosts is 200 m.
For transmitting station A to detect whether any other station transmitted during A 's interval, trans t must be greater than 2 = 2 ⋅ 265 prop t m/1.8 ×108 m/sec = 2.94μ sec. Because 2.94 < 5.76 , A will detect B 's signal before the end of its transmission. 21. Suppose two nodes, A and B, are attached to opposite ends of a 900 m cable, and that they each have one frame of 1000 bits (including all headers and preambles) to send to each other. Both nodes attempt to transmit at time t=0. Suppose there are four repeaters between A and B, each inserting a 20 bit delay. Assume the transmission rate is 10 Mbps, and CSMA/CD with backoff intervals of multiples of 512 bits is used. After the first collision, A draws K=0 and B draws K=1 in the exponential backoff protocol. Ignore the jam signal.
a. What is the one-way propagation delay (including repeater delays) between A and B in seconds. Assume that the signal propagation speed is 2 * 108m/sec.
b. At what time (in seconds) is A's packet completely delivered at B.
c. Now suppose that only A has a packet to send and that the repeaters are replaced with bridges. Suppose that each bridge has a 20 bit processing delay in addition to a store-and-forward delay. At what time in seconds is A's packet delivered at B?
ANS>> a)
= (4.5 10-6+8 10-6)
=12.5µsec
b) frame transmission time is (1000bits/10*106bps)=100 μsec
At time t = 0 , both A and B transmit.
At time t = 12.5μ sec , A detects a collision.
At time t = 25μ sec last bit of B 's aborted transmission arrives at A .
At time t = 37.5μ sec first bit of A 's retransmission arrives at B .
At time t= 37.5 μsec + 100 μsec =137.5 μsecA 's packet is completely delivered at B .
c) 12.5μ sec+ 5⋅100μ sec = 512.5μ sec

PHP interview questions and answers

2010-10-14T20:54:00.002+05:30

1. What does a special set of tags do in PHP?
Ans - The output is displayed directly to the browser.

2. What’s the difference between include and require?
Ans - It’s how they handle failures. If the file is not found by require(), it will cause a fatal error and halt the execution of the script. If the file is not found by include(), a warning will be issued, but execution will continue.

3. I am trying to assign a variable the value of 0123, but it keeps coming up with a different number, what’s the problem?
Ans - PHP Interpreter treats numbers beginning with 0 as octal. Look at the similar PHP interview questions for more numeric problems.

4. Would I use print "$a dollars" or "{$a} dollars" to print out the amount of dollars in this example?
Ans - In this example it wouldn’t matter, since the variable is all by itself, but if you were to print something like "{$a},000,000 mln dollars", then you definitely need to use the braces.

5. How do you define a constant?
Ans - Via define() directive, like define ("MYCONSTANT", 100);

6. How do you pass a variable by value?
Ans - Just like in C++, put an ampersand in front of it, like $a = &$b

7. Will comparison of string "10" and integer 11 work in PHP?
Ans - Yes, internally PHP will cast everything to the integer type, so numbers 10 and 11 will be compared.

8. When are you supposed to use endif to end the conditional statement?
Ans - When the original if was followed by : and then the code block without braces.

9. Explain the ternary conditional operator in PHP?
Ans - Expression preceding the ? is evaluated, if it’s true, then the expression preceding the : is executed, otherwise, the expression following : is executed.

10. How do I find out the number of parameters passed into function?
Ans - func_num_args() function returns the number of parameters passed in.

11. If the variable $a is equal to 5 and variable $b is equal to character a, what’s the value of $$b?
Ans - 100, it’s a reference to existing variable.

12. What’s the difference between accessing a class method via -> and via ::?
Ans - :: is allowed to access methods that can perform static operations, i.e. those, which do not require object initialization.

13. Are objects passed by value or by reference?
Ans - Everything is passed by value.

14. How do you call a constructor for a parent class?
Ans - parent::constructor($value)

15. What’s the special meaning of __sleep and __wakeup?
Ans - __sleep returns the array of all the variables than need to be saved, while __wakeup retrieves them.

16. Would you initialize your strings with single quotes or double quotes?
Ans - Since the data inside the single-quoted string is not parsed for variable substitution, it’s always a better idea speed-wise to initialize a string with single quotes, unless you specifically need variable substitution.

17. How come the code works, but doesn’t for two-dimensional array of mine?
Ans - Any time you have an array with more than one dimension, complex parsing syntax is required. print "Contents: {$arr[1][2]}" would’ve worked.

18. What is the difference between characters �23 and x23?
Ans - The first one is octal 23, the second is hex 23.

19. With a heredoc syntax, do I get variable substitution inside the heredoc contents?
Ans - Yes.

20. I am writing an application in PHP that outputs a printable version of driving directions. It contains some long sentences, and I am a neat freak, and would like to make sure that no line exceeds 50 characters. How do I accomplish that with PHP?
Ans - On large strings that need to be formatted according to some length specifications, use wordwrap() or chunk_split().

21. What’s the difference between htmlentities() and htmlspecialchars()?
Ans - htmlspecialchars only takes care of <, >, single quote ‘, double quote " and ampersand. htmlentities translates all occurrences of character sequences that have different meaning in HTML.

22. What’s the difference between md5(), crc32() and sha1() crypto on PHP?
Ans - The major difference is the length of the hash generated. CRC32 is, evidently, 32 bits, while sha1() returns a 128 bit value, and md5() returns a 160 bit value. This is important when avoiding collisions.

23. So if md5() generates the most secure hash, why would you ever use the less secure crc32() and sha1()?
Ans - Crypto usage in PHP is simple, but that doesn’t mean it’s free. First off, depending on the data that you’re encrypting, you might have reasons to store a 32-bit value in the database instead of the 160-bit value to save on space. Second, the more secure the crypto is, the longer is the computation time to deliver the hash value. A high volume site might be significantly slowed down, if frequent md5() generation is required.

24. How do you match the character ^ at the beginning of the string?
Ans - ^^

Java Thread Questions and answers

2010-10-12T15:14:00.001+05:30

1. Do I need to use synchronized on setValue(int)?
Ans: It depends whether the method affects method local variables, class static or instance variables. If only method local variables are changed, the value is said to be confined by the method and is not prone to threading issues.

2. Do I need to use synchronized on setValue(int)?
Ans: It depends whether the method affects method local variables, class static or instance variables. If only method local variables are changed, the value is said to be confined by the method and is not prone to threading issues.

3. What is the SwingUtilities.invokeLater(Runnable) method for?
Ans: The static utility method invokeLater(Runnable) is intended to execute a new runnable thread from a Swing application without disturbing the normal sequence of event dispatching from the Graphical User Interface (GUI). The method places the runnable object in the queue of Abstract Windowing Toolkit (AWT) events that are due to be processed and returns immediately. The runnable objectrun() method is only called when it reaches the front of the queue. The deferred effect of the invokeLater(Runnable) method ensures that any necessary updates to the user interface can occur immediately, and the runnable work will begin as soon as those high priority events are dealt with. The invoke later method might be used to start work in response to a button click that also requires a significant change to the user interface, perhaps to restrict other activities, while the runnable thread executes.

4. What is the volatile modifier for?
Ans: The volatile modifier is used to identify variables whose values should not be optimized by the Java Virtual Machine, by caching the value for example. The volatile modifier is typically used for variables that may be accessed or modified by numerous independent threads and signifies that the value may change without synchronization.

5. Which class is the wait() method defined in?
Ans: The wait() method is defined in the Object class, which is the ultimate superclass of all others. So the Thread class and any Runnable implementation inherit this method from Object. The wait() method is normally called on an object in a multi-threaded program to allow other threads to run. The method should should only be called by a thread that has ownership of the objectÃ¢â‚¬â„¢s monitor, which usually means it is in a synchronized method or statement block.

6. Which class is the wait() method defined in?
Ans: I get incompatible return type for my threadÃ¢â‚¬â„¢s getState( ) method! - It sounds like your application was built for a Java software development kit before Java 1.5. The Java API Thread class method getState() was introduced in version 1.5. Your thread method has the same name but different return type. The compiler assumes your application code is attempting to override the API method with a different return type, which is not allowed, hence the compilation error.

7. What is a working thread?
Ans: A working thread, more commonly known as a worker thread is the key part of a design pattern that allocates one thread to execute one task. When the task is complete, the thread may return to a thread pool for later use. In this scheme a thread may execute arbitrary tasks, which are passed in the form of a Runnable method argument, typically execute(Runnable). The runnable tasks are usually stored in a queue until a thread host is available to run them. The worker thread design pattern is usually used to handle many concurrent tasks where it is not important which finishes first and no single task needs to be coordinated with another. The task queue controls how many threads run concurrently to improve the overall performance of the system. However, a worker thread framework requires relatively complex programming to set up, so should not be used where simpler threading techniques can achieve similar results.

8. What is a green thread?
Ans: A green thread refers to a mode of operation for the Java Virtual Machine (JVM) in which all code is executed in a single operating system thread. If the Java program has any concurrent threads, the JVM manages multi-threading internally rather than using other operating system threads. There is a significant processing overhead for the JVM to keep track of thread states and swap between them, so green thread mode has been deprecated and removed from more recent Java implementations. Current JVM implementations make more efficient use of native operating system threads.

9. What are native operating system threads?
Ans : Native operating system threads are those provided by the computer operating system that plays host to a Java application, be it Windows, Mac or GNU/Linux. Operating system threads enable computers to run many programs simultaneously on the same central processing unit (CPU) without clashing over the use of system resources or spending lots of time running one program at the expense of another. Operating system thread management is usually optimised to specific microprocessor architecture and features so that it operates much faster than Java green thread processing.

J2ee Interview Questions and Answers

2010-07-09T12:17:00.000+05:30

1. What makes J2EE suitable for distributed multitiered Applications?
Ans : The J2EE platform uses a multitiered distributed application model. Application logic is divided into components according to function, and the various application components that make up a J2EE application are installed on different machines depending on the tier in the multitiered J2EE environment to which the application component belongs. The J2EE application parts are:

* Client-tier components run on the client machine.
* Web-tier components run on the J2EE server.
* Business-tier components run on the J2EE server.
* Enterprise information system (EIS)-tier software runs on the EIS server.

2. What is J2EE?
Ans : J2EE is an environment for developing and deploying enterprise applications. The J2EE platform consists of a set of services, application programming interfaces (APIs), and protocols that provide the functionality for developing multitiered, web-based applications.

3. What do Enterprise JavaBeans components contain?
Ans : Enterprise JavaBeans components contains Business code, which is logic
that solves or meets the needs of a particular business domain such as banking, retail, or finance, is handled by enterprise beans running in the business tier. All the business code is contained inside an Enterprise Bean which receives data from client programs, processes it (if necessary), and sends it to the enterprise information system tier for storage. An enterprise bean also retrieves data from storage, processes it (if necessary), and sends it back to the client program.

4. Is J2EE application only a web-based?
Ans : No, It depends on type of application that client wants. A J2EE application can be web-based or non-web-based. if an application client executes on the client machine, it is a non-web-based J2EE application. The J2EE application can provide a way for users to handle tasks such as J2EE system or application administration. It typically has a graphical user interface created from Swing or AWT APIs, or a command-line interface. When user request, it can open an HTTP connection to establish communication with a servlet running in the web tier.

5. Are JavaBeans J2EE components?
Ans : No. JavaBeans components are not considered J2EE components by the J2EE specification. They are written to manage the data flow between an application client or applet and components running on the J2EE server or between server components and a database. JavaBeans components written for the J2EE platform have instance variables and get and set methods for accessing the data in the instance variables. JavaBeans components used in this way are typically simple in design and implementation, but should conform to the naming and design conventions outlined in the JavaBeans component architecture.

6. Is HTML page a web component?
Ans : No. Static HTML pages and applets are bundled with web components during application assembly, but are not considered web components by the J2EE specification. Even the server-side utility classes are not considered web components, either.

7. What can be considered as a web component?
Ans : J2EE Web components can be either servlets or JSP pages. Servlets are Java programming language classes that dynamically process requests and construct responses. JSP pages are text-based documents that execute as servlets but allow a more natural approach to creating static content.

8. What is the container?
Ans : Containers are the interface between a component and the low-level platform specific functionality that supports the component. Before a Web, enterprise bean, or application client component can be executed, it must be assembled into a J2EE application and deployed into its container.

9. What are container services?
Ans : A container is a runtime support of a system-level entity. Containers provide components with services such as lifecycle management, security, deployment, and threading.

10. What are the components of J2EE application?
Ans: A J2EE component is a self-contained functional software unit that is assembled into a J2EE application with its related classes and files and communicates with other components. The J2EE specification defines the following J2EE components:

1. Application clients and applets are client components.
2. Java Servlet and JavaServer Pages technology components are web components.
3. Enterprise JavaBeans components (enterprise beans) are business components.
4. Resource adapter components provided by EIS and tool vendors.

C Sharp Interview Questions and Answers

2010-07-05T12:18:00.003+05:30

1. What’s the advantage of using System.Text.StringBuilder over System.String?

Ans : StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it’s being operated on, a new instance is created.

2. What’s the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception?

Ans : A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.

3. Can multiple catch blocks be executed?

Ans : No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.

4. Why is it a bad idea to throw your own exceptions?

Ans : Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.

5. How’s the DLL Hell problem solved in .NET?

Ans : Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.

6. What’s a satellite assembly?

Ans : When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.

7. What debugging tools come with the .NET SDK?

Ans : CorDBG – command-line debugger, and DbgCLR – graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch.

8. What does assert() do?

Ans : In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.

9. Why are there five tracing levels in System.Diagnostics.TraceSwitcher?

Ans : The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.

10. What are three test cases you should go through in unit testing?

Ans : Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly).

11. What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET?

Ans : SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it’s a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.

12. Explain ACID rule of thumb for transactions.

Ans : Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no “in-between” case where something has been updated and something hasn’t), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).

IT Fundamental - X

2010-06-27T22:49:00.002+05:30

1. On the motherboard (the) … is the temporary computer memory area in which data can be stored.

a. expansion slot

b. math co-processor

c. RAM

d. ROM BIOS

2. The device used in a data communication network to perform the conversion between analogue and digital signals, is called a …

a. front end processor.

b. modem.

c. decoder.

d. multiplexer.

3.If you look carefully at the motherboard, you will notice that some chips are soldered to the board whilst others are plugged into the board. The removable chips allow you to ...

a. add extra power sources to your computer.

b. integrate the ALU and the system clock unit.

c. re-arrange the layout of your motherboard.

d. upgrade your computer components.

4. The Internet offers different services. Which one listed below is incorrect?

a. Chat room

b. Electronic mail

c. Off line shopping

d. World Wide Web

5. The Internet is ...

a. a global network of computers networks.

b. a government-owned agency that links computers.

c. software for sending e-mail around the world.

d. a specialised form of local area network.

6. The CPU deals with each instruction in a cycle. The sequence of instructions to carry out one machine instruction is called the instruction or machine cycle. The first action is to fetch the instruction from memory and then the program counter is updated (reset). The other three phases of the machine cycle in the correct order are:

a. Decode the instruction; Execute the instruction; Transfer the data.

b. Decode the instruction; Transfer the data; Execute the instruction.

c. Execute the instruction; Decode the instruction; Transfer the data.

d. Transfer the data; Execute the instruction; Decode the instruction.

7. When the electrical power is disrupted or cut off, data and programs are lost in/on (the) ...

a. basic tools.

b. hard disk.

c. memory.

d. secondary storage.

8. The communication bus which is used to fetch the address of an instruction from memory is called the …

a. address bus.

b. control bus.

c. data bus.

d. fetch bus.

9. Read Only Memory (ROM)

i. Is volatile

ii. Is programmable

iii. Is mounted on the mother board

iv. Contains the bootstrap loader

a. i and iii

b. i, ii and iv

c. ii, iii and iv

d. iii and iv

10. An online meeting allows users to ...

a. determine the receiver's geographic location.

b. leave voice messages for one or two people.

c. print to a web address that is associated to a particular printer.

d. share documents with others in real time.

Software Engg. - III

2010-06-18T11:32:00.000+05:30

1) Business model is the part of designing phase of software engineering development life cycle

a. True

b. False

2) The state transition diagram

a. depicts relationships between data objects

b. depicts functions that transform the data flow

c. indicates how data are transformed by the system

d. indicates system reactions to external events

3) The best way to conduct a requirements validation review is to

a. Examine the system

b. Have the customer look over the requirements

c. Send them to the design team

d. Use checklist to examine the questions

4) The system specification describes the

a. Function, performance and constraints of a computer-based system

b. implementation of each allocated system

c. time required for simulation

d. element software architecture

5) For each of the following given Requirement indicate whether it is Functional (F) or Non-Functional (N) Requirement.

a. The System should be designed so it can later be extended to a Blue Line

reservation System.(N)

b. The System will allow the user to view the layout of seats in Bus.(F)

c. The System must be available at all times.(N)

d. A given seat can be assigned to only one person.(F)

6)Both the software engineer and customer take an active role in software requirements engineering-a set of activities that is often referred to as Requirement_______________

a. Managing

b. Recognition

c. Analysis

d. Modeling

7)_________ is a measure of independence of a module or component.

a. Cohesion

b. Coupling

c. Loop coupling

d. Loop cohesion

8) In the Functional design, the structure of the system revolves around __________

a. Functions

b. Sequences

c. Models

d. Flows

9)Use case is the part of designing phase of software engineering

a. True

b. False

10) Three categories of risks are

a. Business, personnel risks, budget risks

b. project risks, technical risks, business risks

c. planning risks, technical risks, personnel risks

d. management risks, technical risks, design risks

Software Engg. - II

2010-06-13T23:04:00.002+05:30

1. Decomposing the major project deliverables into smaller, more manageable components to provide better control is called:

a) Project planning.

b) Scope definition.

c) Project base lining.

d) Requirements verification.

2. Select one aspect that is NOT included in a feasibility analysis for new system?

a) Organisational objectives

b) Cost effectiveness

c) Technical feasibility

d) Budgetary constraints

e) Requirements validation

3. One of the fundamental tenets of quality management is that quality:

a) Must exceed customer expectations.

b) Is planned in and not inspected in.

c) Will increase cost.

d) Costs must all be passed onto the customer.

4. In the Shewhart and Deming Quality cycle, the letters P D C A stands for:

a) Purchase, deliver, cost, and acquisition.

b) Prevent defects caused by anyone.

c) Plan, do, check, and act.

d) Please don’t cause accidents.

5. Which is NOT included in the software requirements specification?

a) test specifications for each mandatory requirement

b) project schedule and WBS

c) functional description of user requirements

d) performance description for each non-functional requirement

e) data dictionary

6. A data dictionary was created during the requirements analysis phase of a software engineering project. What information does it contain?

a) interface design criteria

b) data types and description of database table entries

c) restrictions on security

d) list of main functional requirements

7. A software project classifies system entities, their activities and relationships. The classification and abstraction of system entities is important. Which modelling methodology most clearly shows the classification and abstraction of entities in the system?

a) data flow model

b) event driven model

c) object oriented model

d) entity-relationship model

8. Which of the following is NOT a non-functional system requirement component?

a) cost

b) reliability

c) usability

d) performance

e) maintainability

9. What is the purpose of a test case specification in software engineering?

a) to specify the sequence of actions for the execution of a number of sequential tests

b) to specify inputs, predicted results, and a set of execution conditions for a test item

c) to list the test procedures to be performed on the integration of the system database

d) to report the specific tests results when integrating software modules

10. In the software testing process, when is validation testing performed?

a) after coding

b) after unit testing

c) after module testing

d) after integration testing

C# DotNet Questions

2010-06-12T10:11:00.000+05:30

1. What’s the implicit name of the parameter that gets passed into the class’ set method?

Value, and its datatype depends on whatever variable we’re changing.

2. How do you inherit from a class in C#?

Place a colon and then the name of the base class. Notice that it’s double colon in C++.

3. Does C# support multiple inheritance?

No, use interfaces instead.

4. When you inherit a protected class-level variable, who is it available to?

Classes in the same namespace.

5. Are private class-level variables inherited?

Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are.

6. Describe the accessibility modifier protected internal.

It’s available to derived classes and classes within the same Assembly (and naturally from the base class it’s declared in).

7. C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write?

Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there’s no implementation in it.

8. What’s the top .NET class that everything is derived from?

System.Object.

9. How’s method overriding different from overloading?

When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class.

10. What does the keyword virtual mean in the method definition?

The method can be over-ridden.

11. Can you declare the override method static while the original method is non-static?

No, you can’t, the signature of the virtual method must remain the same, only the keyword virtual is changed to keyword override.

12. Can you override private virtual methods?

No, moreover, you cannot access private methods in inherited classes, have to be protected in the base class to allow any sort of access.

13. Can you prevent your class from being inherited and becoming a base class for some other classes?

Yes, that’s what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It’s the same concept as final class in Java.

14. Can you allow class to be inherited, but prevent the method from being over-ridden?

Yes, just leave the class public and make the method sealed.

15. What’s an abstract class?

A class that cannot be instantiated. A concept in C++ known as pure virtual method. A class that must be inherited and have the methods over-ridden. Essentially, it’s a blueprint for a class without any implementation.

Java Fundamental-X

2010-05-23T18:55:00.001+05:30

1. What is J2EE Connector?

The J2EE Connector API is used by J2EE tools vendors and system integrators to create resource adapters that support access to enterprise information systems that can be plugged into any J2EE product. Each type of database or EIS has a different resource adapter.

2. What is JAAP?

The Java Authentication and Authorization Service (JAAS) provide a way for a J2EE application to authenticate and authorize a specific user or group of users to run it. It is a standard Pluggable Authentication Module (PAM) framework that extends the Java 2 platform security architecture to support user-based authorization.

3. What is Model 1?

Using JSP technology alone to develop Web page. Such term is used in the earlier JSP specification. Model 1 architecture is suitable for applications that have very simple page flow, have little need for centralized security control or logging, and change little over time. Model 1 applications can often be refactored to Model 2 when application requirements change.

4. What is Model 2?

Using JSP and Servlet together to develop Web page. Model 2 applications are easier to maintain and extend, because views do not refer to each other directly.

5. What is Struts?

A Web page development framework. Struts combine Java Servlets, Java Server Pages, custom tags, and message resources into a unified framework. It is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone between.

6. How is the MVC design pattern used in Struts framework?

In the MVC design pattern, application flow is mediated by a central Controller. The Controller delegates requests to an appropriate handler. The handlers are tied to a Model, and each handler acts as an adapter between the request and the Model. The Model represents, or encapsulates, an application's business logic or state. Control is usually then forwarded back through the Controller to the appropriate View. The forwarding can be determined by consulting a set of mappings, usually loaded from a database or configuration file. This provides a loose coupling between the View and Model, which can make an application significantly easier to create and maintain.

Controller--Servlet controller which supplied by Struts itself; View --- what you can see on the screen, a JSP page and presentation components; Model --- System state and a business logic JavaBeans.

7. What does web module contain?

The web module contains:

o JSP files,

o class files for Servlets,

o GIF and HTML files, and

o A Web deployment descriptor.

Web modules are packaged as JAR files with a .war (Web Archive) extension.

8. What APIs are available for developing a J2EE application?

o Enterprise JavaBeans Technology(3 beans: Session Beans, Entity Beans and Message-Driven Beans)

o JDBC API(application level interface and service provider interface or driver)

o Java Servlets Technology(Servlet)

o Java ServerPage Technology(JSP)

o Java Message Service(JMS)

o Java Naming and Directory Interface(JNDI)

o Java Transaction API(JTA)

o JavaMail API

o JavaBeans Activation Framework(JAF used by JavaMail)

o Java API for XML Processing(JAXP,SAX, DOM, XSLT)

o Java API for XML Registries(JAXR)

o Java API for XML-Based RPC(JAX-RPC)-SOAP standard and HTTP

o SOAP with Attachments API for Java(SAAJ)-- low-level API upon which JAX-RPC depends

o J2EE Connector Architecture

o Java Authentication and Authorization Service(JAAS)

Java Fundamental-IX

2010-05-08T23:45:00.000+05:30

1. Are JavaBeans J2EE components?

NO. JavaBeans components are not considered J2EE components by the J2EE specification. JavaBeans components written for the J2EE platform have instance variables and get and set methods for accessing the data in the instance variables. JavaBeans components used in this way are typically simple in design and implementation, but should conform to the naming and design conventions outlined in the JavaBeans component architecture.

2. Is HTML page a web component?

NO. Static HTML pages and applets are bundled with web components during application assembly, but are not considered web components by the J2EE specification. Even the server-side utility classes are not considered web components, either.

3. What is the container?

A container is a runtime support of a system-level entity. Containers provide components with services such as lifecycle management, security, deployment, and threading.

4. What is the web container?

Servlet and JSP containers are collectively referred to as Web containers.

5. What is the thin client?

A thin client is a lightweight interface to the application that does not have such operations like query databases, execute complex business rules, or connect to legacy applications.

6. What are types of J2EE clients?

o Applets

o Application clients

o Java Web Start-enabled rich clients, powered by Java Web Start technology.

o Wireless clients, based on Mobile Information Device Profile (MIDP) technology.

7. What is deployment descriptor?

A deployment descriptor is an Extensible Markup Language (XML) text-based file with an .xml extension that describes a component's deployment settings. A J2EE application and each of its modules has its own deployment descriptor.

8. What is the EAR file?

An EAR file is a standard JAR file with an .ear extension, named from Enterprise Archive file. A J2EE application with all of its modules is delivered in EAR file.

9. What are JTA and JTS?

JTA is the abbreviation for the Java Transaction API. JTS is the abbreviation for the Java Transaction Service. JTA provides a standard interface and allows you to demarcate transactions in a manner that is independent of the transaction manager implementation. The J2EE SDK implements the transaction manager with JTS. But your code doesn't call the JTS methods directly. Instead, it invokes the JTA methods, which then call the lower-level JTS routines.

Therefore, JTA is a high level transaction interface that your application uses to control transaction. And JTS is a low level transaction interface and EJBs uses behind the scenes (client code doesn't directly interact with JTS. It is based on object transaction service (OTS) which is part of CORBA.

10. What is JAXP?

JAXP stands for Java API for XML. XML is a language for representing and describing text-based data which can be read and handled by any program or tool that uses XML APIs.

Java Fundamental-VIII

2010-05-02T10:04:00.001+05:30

1. What is J2EE?

J2EE is an environment for developing and deploying enterprise applications. The J2EE platform consists of a set of services, application programming interfaces (APIs), and protocols that provide the functionality for developing multi tiered, and web-based applications.

2. What is the J2EE module?

A J2EE module consists of one or more J2EE components for the same container type and one component deployment descriptor of that type.

3. What are the components of J2EE application?

A J2EE component is a self-contained functional software unit that is assembled into a J2EE application with its related classes and files and communicates with other components. The J2EE specification defines the following J2EE components:

o Application clients and applets are client components.

o Java Servlets and Java Server Pages TM (JSPTM) technology components are web components.

o Enterprise JavaBeansTM (EJBTM) components (enterprise beans) are business components.

o Resource adapter components provided by EIS and tool vendors.

4. What are the four types of J2EE modules?

1. Application client module

2. Web module

3. Enterprise JavaBeans module

4. Resource adapter module

5. What does application client module contain?

The application client module contains:

o class files,

o an application client deployment descriptor.

Application client modules are packaged as JAR files with a .jar extension.

6. What does Enterprise JavaBeans module contain?

The Enterprise JavaBeans module contains:

o class files for enterprise beans

o An EJB deployment descriptor.

EJB modules are packaged as JAR files with a .jar extension.

7. What does resource adapt module contain?

The resource adapt module contains:

o all Java interfaces,

o classes,

o native libraries,

o other documentation,

o A resource adapter deployment descriptor.

Resource adapter modules are packages as JAR files with a .rar (Resource adapter Archive) extension.

8. Is J2EE application only a web-based?

NO. A J2EE application can be web-based or non-web-based. If an application client executes on the client machine, it is a non-web-based J2EE application. The J2EE application can provide a way for users to handle tasks such as J2EE system or application administration. It typically has a graphical user interface created from Swing or AWT APIs, or a command-line interface. When user request, it can open an HTTP connection to establish communication with a Servlet running in the web tier.

Database System-V

2010-04-28T13:28:00.001+05:30

1. What is View?

A simple view can be thought of as a subset of a table. It can be used for retrieving data, as well as updating or deleting rows. Rows updated or deleted in the view are updated or deleted in the table the view was created with. It should also be noted that as data in the original table changes, so does data in the view, as views are the way to look at part of the original table. The results of using a view are not permanently stored in the database . The data accessed through a view is actually constructed using standard T-SQL select command and can come from one to many different base tables or even other views.

2. What is Index?

An index is a physical structure containing pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possible to create an index on one or more columns of a table, and each index is given a name. The users cannot see the indexes, they are just used to speed up queries. Effective indexes are one of the best ways to improve performance in a database application.
A table scan happens when there is no index available to help a query. In a table scan SQL Server examines every row in the table to satisfy the query results. Table scans are sometimes unavoidable, but on large tables, scans have a terrific impact on performance. Clustered indexes define the physical sorting of a database table’s rows in the storage media. For this reason, ea ch database table may have only one clustered index. Non-clustered indexes are created outside of the database table and contain a sorted list of references

to the table itself.

3. What is the difference between clustered and a non-clustered index?

A clustered index is a special type of index that reorders the wa y records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages. A nonclustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a nonclustered index does not consist of the data pages. Instead, the leaf nodes contain index rows.

4. What are the different index configurations a table can have?

A table can have one of the following index configurations:

a. No indexes

b. A clustered index

c. A clustered index and many nonclustered indexes

d. A nonclustered index

e. Many nonclustered indexes

5 .What is cursors?

Cursor is a database object used by applications to manipulate data in a set on a row-by-row basis, instead of the typical SQL commands that operate on all the rows in the set at one time. In order to work with a cursor we need to perform some steps in the following order:

a. Declare cursor

b. Open cursor

c. Fetch row from the cursor

d. Process fetched row

e. Close cursor

f. Deallocate cursor

Database System-IV

2010-04-19T11:18:00.001+05:30

1. What is RDBMS?

Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained a cross and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers. This allows a high degree of data independence. An RDBMS ha s the capability to recombine the data items from different files, providing powerful tools for data usage.

2. What is normalization?

Database normalization is a data design and organization process applied to data structures based on rules that help build relational databases. In relational database design, the process of organizing data to minimize redundancy. Normalization usually involves dividing a database into two or more tables and defining relationships between the tables. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.

3. What are different normalization forms?

1NF: Eliminate Repeating Group

Make a separate table for each set of related attributes, and give each table a primary key. Each field contains at most one value from its attribute domain.

2NF: Eliminate Redundant Data

If an attribute depends on only part of a multi-valued key, remove it to a separate table.

3NF: Eliminate Columns Not Dependent On Key

If attributes do not contribute to a description of the key, remove them to a separate table. All attributes must be directly dependent on the primary key

BCNF: Boyce-Codd Normal Form

If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.

4NF: Isolate Independent Multiple Relationships

No table may contain two or more 1:n or n:m relationships that are not directly related.

5NF: Isolate Semantically Related Multiple Relationships

There may be practical constrains on information that justify separating logically related many-to-many relationships.

ONF: Optimal Normal Form

A model limited to only simple (elemental) facts, as expressed in Object Role Model notation.

DKNF: Domain-Key Normal Form

A model free from all modification anomalies.

Remember, these normalization guidelines are cumulative. For a database to be in 3NF, it must first

fulfill all the criteria of a 2NF and 1NF database.

4. What is Stored Procedure?

A stored procedure is a named group of SQL statements that have been previously created and stored in the server database. Stored procedures accept input parameters so that a single procedure can be used over the network by several clients using different input data. And when the procedure is modified, all clients automatically get the new version. Stored procedures reduce network traffic and improve performance. Stored procedures can be used to help ensure the integrity of the database.

e.g. sp_helpdb, sp_renamedb, sp_depends etc.

5. What is Trigger?

A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE)

occurs. Triggers are stored in and managed by the DBMS.Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or executed; the DBMS automatically fires the trigger as a result of a data modification to the associated table.

Triggers can be viewed as similar to stored procedures in that both consist of procedural logic that is stored at the database level. Stored procedures, however, are not event-drive and are not atta ched to a specific table as triggers are. Stored procedures are explicitly executed by invoking a CALL to the procedure while triggers are implicitly executed. In addition, triggers can also execute stored procedures.

Nested Trigger: A trigger can also contain INSERT, UPDATE and DELETE logic within itself, so when the trigger is fired because of data modification it can also cause another data modification, thereby firing another trigger. A trigger that contains data modification logic within itself is called a nested trigger.

IT Fundamental - IX

2010-04-14T23:58:00.000+05:30

1. Array is:

(a) linear data structure

(b) non-linear structure

(d) All of the above

2. A data structure in which elements are added and removed from only one end, is known as:

(a) Array

(b) Stack

(d) None of the above

3. A diamond-shaped box in an Entity-Relationship diagram refers to:

(a) Entity

(b) Relationship

(d) Domain

4. The principle means of identifying entities within an entity set is:

(a) Primary Key

(b) Record

(d) Tuple

5. Modem refers to:

(a) Modulator

(b) Modulation

(d) Modulator and Demodulator

6. C language is available for which of the following Operating Systems?

(a) DOS

(b) Windows

(d) All of the above

7. Which of the following have the fastest access time?

(a) Magnetic Tapes

(b) Magnetic Disks

(d) Compact Disks

8. DMA stands for:

(a) Direct Memory Allocation

(b) Distinct Memory Allocation

(d) Distinct Memory Access

9. Array subscripts in C always start at:

(a):1

(b) 0

(d) Value provided by user

10. Which type of commands in DOS needs additional files for their execution?

(a) Batch Commands

(b) Internal Commands

(d) Main Commands

IT Fundamental - VIII

2010-04-06T23:01:00.000+05:30

1. What is the name of the software that allows us to browse through web pages?

(a) Browser

(b) Mail Client

(d) Messenger

2. What is the address given to a network called?

(a) System Address

(b) SYSID

(d) IP Address

3. Which one of the following is a valid DOS command?

(a) LIST *.*

(b) LIST???.???

(d) RENAME A:SAMPLE.TXT C:TEST.DOC

4. All system settings in WINDOWS are stored in:

(a) CONTROL.INI

(b) MAIN.INI

(d) SETTING.INI

5. Which number system is usually followed in a typical 32-bit computer?

(a) 2

(b) 10

(d) 32

6. Which of the following is not an output device:

(a) Printer

(b) Scanner

(d) Touch Screen

7. A microprocessor is a processor with reduced

(a) instruction set

(b) power requirement

(d) none of the above

8. Which of the following is not an output of an assembler?

(a) executable program

(b) source listing with line numbers and errors

(d) object program

9. Which layer of OSI model is responsible for routing and flow control:

(a) Presentation

(b) Transport

(d) Data Link

10. Arrays are passed as arguments to a function by

(a) value

(b) reference

(d) none of the above

IT Fundamental - VII

2010-03-24T12:08:00.001+05:30

1. Which of the following arrangements of general-purpose data structures is from slowest to fastest for the purpose of finding objects according to a key value:

a. sorted arrays, unsorted linked lists, hash tables, binary search trees

b. sorted arrays, binary search trees, linked lists, hash tables

c. hash tables, binary search trees, unsorted arrays, sorted linked lists

d. sorted linked lists, sorted arrays, binary search trees, hash tables

2. Which of the following arrangements of general-purpose data structures is from slowest to fastest for the purpose of storing objects by key value (not necessarily in order):

a. unsorted arrays, sorted linked lists, hash tables, binary search trees

b. sorted arrays, binary search trees, linked lists, hash tables

c. hash tables, binary search trees, sorted arrays, sorted linked lists

d. unsorted arrays, linked lists, binary search trees, hash tables

3. In an abstract data type, access is often limited to certain items. Which of the following is not such an abstract data type?

a. binary search tree

b. priority queue

c. queue

d. stack

4. Which of the following is not a basic data structure that could be used to implement an abstract data type?

a. array

b. linked list

c. hash table

d. heap

5. Which of the following statements is true?

a. An abstract data type can be conveniently searched for an item by key.

b. An abstract data type can be conveniently traversed.

c. An abstract data type is an interface within a program that simplifies problems.

d. An abstract data type is a database for direct user-accessible data.

6. Which of the following methods of implementing a priority queue is best when both insertion and deletion need to be reasonably fast?

a. ordered array

b. ordered linked list

c. heap

d. binary search tree

7. If the amount of data to be stored in a stack cannot be predicted, the best data structure to implement the stack is:

a. hash table

b. binary search tree

c. linked list

d. unordered array

8. Which of the following statements is true regarding a queue?

a. It may be implemented either by an array or a linked list.

b. It may be implemented by a heap because first in is first out.

c. It may be implemented by a linked list because insertions and deletions may be from the same end.

d. It may be implemented by an array without providing for wrap-around.

9. Which of the following sort algorithms is not an O(n2) sort?

a. shell sort

b. insertion sort

c. selection sort

d. bubble sort

10. Which of the following is true regarding the efficiency of the shell sort?

a. It is slower than O(n2).

b. It is faster than O(n*log2 n).

c. It is not as efficient as the insertion sort.

d. It has not been established theoretically, i.e. as a single function of n.

IT Fundamental - VI

2010-02-26T15:49:00.003+05:30

1. Database software allows users to __________.

a. add, change, and delete data

b. sort and retrieve data from the database

c. create forms and reports using the data in the database

d. all of the above

2. The results of presentation graphics software programs normally are viewed as __________.

a. macros

b. audience handouts

c. slides

d. notes pages

3. A clip art/image gallery can be stored on a __________.

a. hard disk

b. CD-ROM

c. DVD-ROM

d. all of the above

4. A(n) __________ is a PIM feature that can be used to record ideas, reminders, and other important information.

a. appointment calendar

b. address book

c. notepad

d. worksheet

5. Integrated software is __________.

a. less expensive than a less powerful software suite

b. more expensive than a less powerful software suite

c. less expensive than a more powerful software suite

d. more expensive than a more powerful software suite

6. Popular software suites used in schools usually include all of the following applications except __________.

a. word processing

b. spreadsheet

c. calendar

d. database

7. Integrated software and software suites offer all of the following advantages except __________.

a. lower cost

b. ease of use

c. higher cost

d. applications use a similar interface

8. Microsoft FrontPage and Netscape Composer are examples of __________ software.

a. educational

b. Web page authoring

c. reference

d. personal computer entertainment

9. On-screen talking calculators, speech synthesis software programs, and text enlargement software are examples of __________ software.

a. special needs

b. home design/landscaping

c. reference

d. personal computer entertainment

10. Tutorials are __________.

a. answers to questions that people frequently ask about an application

b. the electronic equivalent of a user manual, usually integrated into an application software package

c. step-by-step instructions using real examples to show how to use an application

d. automated assistants that help complete a task by asking questions and performing actions based on the answers

IT Fundamental-V

2010-02-22T11:26:00.001+05:30

1. One type of system software, the operating system __________.

a. contains instructions that coordinate a computer's activities

b. is only important when a computer processes information

c. is not loaded into memory when a computer is first turned on

d. is loaded into memory from a floppy disk each time a computer is turned on

2. Application software can be used __________.

a. as a productivity/business tool and to facilitate communications

b. to assist with graphics and multimedia projects

c. to support household activities, for personal business, or for education

d. all of the above

3. A(n) __________ is a graphical element (usually rectangular or circular in shape) that can be clicked to cause a specific action to take place.

a. button

b. icon

c. menu

d. window

4. An application can be started by __________.

a. dragging its icon over the Start button

b. pointing at a command followed by an arrow

c. clicking its program name on a menu or submenu

d. all of the above

5. __________ involves developing a word processing document by entering text or numbers, inserting graphical images, and performing other tasks using an input device.

a. Creating

b. Editing

c. Formatting

d. Printing

6. To cut involves removing a portion of a document and electronically storing it in a temporary storage location called the __________.

a. Warehouse

b. Cupboard

c. Desktop

d. Clipboard

7.__________ involves changing the appearance of a word processing document.

a. Creating

b. Editing

c. Formatting

d. Printing

8. A __________ is a special window displayed by a program to provide information, present available options, or request a response.

a. menu

b. dialog box

c. title bar

d. submenu

9. Wizards are __________.

a. answers to questions that people frequently ask about an application

b. the electronic equivalent of a user manual, usually integrated into an application software package

c. step-by-step instructions using real examples to show how to use an application

d. automated assistants that help complete a task by asking questions and performing actions based on the answers

10. The __________ entered in a spreadsheet cell identifies the data and helps organize the worksheet.

a. label

b. value

c. formula

d. function

IT Fundamental-IV

2010-01-28T12:23:00.013+05:30

1. A group of interrelated or interacting elements forming a unified whole can be best defined as:

a. Communication technologies.

b. An information system.

c. A company network.

d. Interorganizational system.

2. The majority of organizations today would be classified as:

a. Open nonadaptive systems.

b. Closed nonadaptive systems.

c. Open adaptive systems.

d. Closed adaptive systems.

3. Which one of the following would NOT be considered a good example of information?

a. The company's forklift operator's social security number is 456-38-1276.

b. The retail price of blue widgets is $28.99.

c. The company owes $3,847 to vendor number 10782.

d. The numbers 12367892, 436897458, and 837621984.

4. In the internetworked e-business enterprise, an extranet refers to:

a. A network inside the enterprise.

b. A network between an enterprise and its trading partners.

c. A local area network within the enterprise.

d. A wide area network within the enterprise.

5. A manager needs to have summary sales information by product line available to her on a timely basis when purchasing decisions need to be made. The type of information system most likely to provide this information is a:

a. Management information system.

b. Decision support system.

c. Transaction processing system.

d. Process control system.

6. A physician wants an information system that can help in the diagnosis of rare diseases by suggesting diagnostic procedures and help in interpreting the symptoms that are found. This type of information system is called a(n):

a. End user information system.

b. Integrated information system.

c. Executive information system.

d. Expert system.

7. Developing new products and services that are fundamentally different from the way business has been conducted in an industry would be considered a(n):

a. Cost leadership strategy.

b. Innovation strategy.

c. Product differentiation strategy.

d. Strategic dominance strategy.

8. Establishing new business linkages and alliances with customers, suppliers, and competitors is an example of a(n):

a. Alliance strategy.

b. Differentiation strategy.

c. Innovation strategy.

d. Gowth strategy.

9. Charles Schwab & Company's use of online discount stock trading is an example of the way in which a firm can use strategic information system technology. Their primary competitive strategy was to:

a. Establish cost leadership.

b. Improve operational efficiency.

c. Promote business innovation.

d. Build strategic information resources.

10. The value chain views a series, chain, or network of basic activities that add value to products and services. One of the primary activities in a firm's "value chain" typically includes:

a. Outbound logistics.

b. Procurement of resources.

c. Human resource management.

d. Technology development.

Points about OOPS

2010-01-16T18:53:00.003+05:30

1. Abstraction is the process of highlighting the essential, inherent aspects of an entity while ignoring irrelevant details.

2. Encapsulation (or information hiding) is the process of separating the external aspects of an objects from the internal implementation details which should be hidden from other objects.

3. Modularity is the process of dividing a problem into smaller pieces so that each smaller module can be dealt with individually.

4. Organizing a set of abstractions from most general to least is known as inheritance hierarchy.

5. Object-oriented programming is a paradigm in which a system is modeled as a set of objects that interact with each other.

6. In C++ an abstraction is formed by creating a class. A class encapsulates the attributes and behaviors of an object.

7. The data members of a class represent the attributes of a class. And the member functions of a class represents the behaviors of a class.

8. Polymorphism is the capability of something to assumediferent forms. In an object-oriented language, polymorphism is provided by allowing a message or member function to mean different things depending on the type of object that receives the message.

9. All C++ program begin executing from the main. Function main returns an integer value that indicates whether the program executed successfullly or not. A value of ) indicates successful execution, while the value 1 indicates that a problem or error occurred during the execution of the program.

10. A variable must be defined before it can be used. Smart programmers give a variable an initial value when it is defined.

11. A pointer is a variable whose value is the address of another variable.

12. Pointers should be different type for each type of variable. There are even pointer types whose variable are pointers to other pointers.

13. The location of a variable can be obtained using the address operator &.

14. Pointer operators may be compared using the equality and relational operators.

15. The increment and decrement operators may be applied to pointer objects.

16. Pointers can be passed as reference parameters by using the indirection operator.

17. Command-line parameters are communicated to programs using pointers.

18. We can define variables that are pointers to functions. Such variables are typically used as function parameters. This type of parameter enables the function that uses it to have greater flexibility in accomplishing its task.

19. A reference variable must be initialized when it is declared.

20. When a reference parameter is used, instead of passing a copy of the variable, a reference to the original variable is passed. Any modifications made to the parameter by the called function change the original variable.

21. A reason to use reference parameter is for efficiency. When a class object is passed by value, a copy of the object is passed. If the object is large, making a copy of it can be expensive in terms of execution time and memory space. thus, objects that are large, or objects whose size is not known are often passed by reference. We can ensure that the objects are not modified by using the const modifier.

22. Constructors initialize objects of the class type. It is standard practice to ensure that every object has all of its data members appropriately initializes.

23. A default constructor is a constructor that requires no parameters.

24. A copy constructor initialize a new object to be a duplicate of a previously defined source object. If a class does not define a copy constructor, the compiler automatically supplies version.

25. A class constructor, if defined, is called whenever a program creates an object of that class.
26. An inline function must be defined before it is called.
27. An inline function reduces the function call overhead. Small functions are best declared inline within a class.