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Reasoning revision short Quiz .

2020-04-12T00:41:00.000+05:30

Here are some easy Reasoning Quiz for revision.

Answer them properly and in the end you can check your score and others score also.

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GK mcq

2020-03-01T14:32:00.002+05:30

SSC Junior Engineers Exam. 2012 – GK Paper

SSC Junior Engineers (Civil, Mechanical, Electrical,Quantity Surveying and Contract) Examination

Solved GK Paper :-

1. Birmingham is an Industrial Center of
a) The Keihin region
b) The Pittsburg-Lake Erie region
c) Volga region
d) The Midlands

2. A crescent shaped dune is known as
a) Zeugen
b) Barkhan
c) Sandbar
d) Seif

3. Which is an ore of dolomite?
a) Lead
b) Aluminium
c) Magnesium
d) Copper

4. Stalactites and stalagmites are found mainly in
a) limestone regions
b) underground coal mines
c) sandstone regions
d) granite regions

5. Which one of the following is oldest and depest fresh water lake in the world?
a) Lake Titicaca
b) Lake Baikal
c) Lake Chilka
d) Lake Superior

Lake Baikal in Siberia, Russia, contains 20 percent of the world’s freshwater, and it is large enough to hold all
the water in the United States’ Great Lakes. It is the world’s deepest (1,638 metres deep) lake as well as its
oldest; at 25 million years old, it predates the emergence of humans.

6. Which one of the following plants shows vivipary?
a) Litchi
b) Rhizophora
c) Mango
d) Pinus

7. The kind of inflorescence in sunflower is
a) Spike
b) Capitulum
c) Raceme
d) Spadix

8. Moulting in insects is mainly controlled by
a) Parahormone
b) Parathormone
c) Ecdysone
d) Ecotone

Molting is the process by which insects grow. It allows the body of the insect to expand under controlled
and protected conditions. Insects grow in increments; in fact, all arthropods do. Each stage of growth ends
with molting, the process of shedding and replacing the rigid exoskeleton.This exoskeleton is basically their
underlying bone structure that is located on the outside of their bodies with corresponding organs and muscles
located underneath this hard shell. Ecdysone is the major steroid hormone in insects and plays essential roles
in coordinating developmental transitions such as larval molting.

9. Silver fish is included in the phylum
a) Echinodermata
b) Chordata
c) Arthopoda
d) Annelida

10. ‘Liver rot’ is caused by
a) Taenia
b) Typhlops
c) Trypanosoma
d) Fasciola

11. ”Proconvertin” is an example of
a) Glycoprotein
b) Plasma protein
c) Proteolipid
d) Lipoprotein

12. If the filament current of a coolidge-tube is increased, X-rays emitted from it will be greater
a) intensity
b) velocity
c) peneteration power
d) energy

If the filament current in a Coolidge tube is increased by increasing the voltage in the filament circuit, more
electrons are emitted per unit time. This result in an increase in the number of X photons emitted per unit time
and hence the intensity of X-rays is increased.

13. The idea of stationary orbit of electrons in an atom was first introduced by
a) Rutherford
b) Bohr
c) Thomson
d) Sommerfield

14. Which of the following pairs of particles have equal and opposite charge?
a) Electron – Neutron
b) Proton – Neutron
c) Electron – Proton
d) None of these

15. In ‘Isobaric process’, which parameter remains constant?
a) Volume
b) Temperature
c) Mass
d) Pressure

A process in which the pressure of the system remains constant during a change of state is called a
constant-pressure or isobaric process.

16. A prototype of a system is
a) The source code of a fully developed system
b) The object code of a fully developed system
c) A complete system
d) A trial version of a system under development

17. An example of a mathematical function in Structured Query language (SQL) is
a) MAX
b) MIN
c) COS
d) AVG

SQL provides plenty of standard math functions such as ACOS, COS, TAN, ATAN, ASIN, CEILING, FLOOR, etc.
They work like the math concepts you may have studied in school. Most are self explanatory.
SQL provides aggregate functions to assist with the summarization of large volumes of data. For example:
AVG – Returns the average value of a column over a result set
COUNT – Returns a count of rows over a result set
FIRST – Returns the first value of a column in a result set
LAST – Returns the last value of a column in a result set
MIN – Returns the minimum value of a column over a result set
MAX – Returns the maximum value of a column over a result set
SUM – Returns a sum of a column over a result set

18. The intensity of sound is measured in dB-sclae and the threshold of hearing is
a) 5 dB
b) 10 dB
c) 20 dB
d) 0 dB
The lowest possible sound that can be heard is called the threshold of hearing. The threshold of hearing is
assigned a sound level of 0 decibels (abbreviated 0 dB). The sound level at the threshold of hearing
corresponds to an intensity of 1*10-12 W/m2. Intensity of sound is measured in Watts per square meter.
19. PAN is a pollutant of air. The full name of PAN is
a) Peroxy Aldehyal Nitrate
b) Peroxy Acetyl Nitrate
c) Peroxy Acidal Nitrate
d) Peroxy Alkyl Nitrate

20. Repeated exposure to small concentrations of a toxic agent results in accumulation of toxic
sunstance over a period of time. This is known as
a) Chronic toxicity
b) Bio accumulation
c) Chronic accumulation
d) Biomagnification

21. Which one of these elements is NOT considered an essential trace element for the biosphere?
a) Selenium
b) Molybdenum
c) Sodium
d) Zinc

22. The term epicentre is associated with
a) earthquakes
b) folding
c) earth’s interior
d) faulting

23. How many countries patricipated in first Twenty-20 World Cup in South Africa?
a) 28
b) 16
c) 12
d) 32

24. Which one among the following is the national Fruit?
a) Jack Fruit
b) Apple
c) Mango
d) Banana

25. Which language is spoken by maximum number of people in the world?
a) Chinese
b) Spanish
c) Urdu
d) English

26. Name the dome shaped monument used to keep Buddhist relics
a) Chaityas
b) Viharas
c) Temples
d) Stupa

27. ‘KIMONO’ is a dress style of
a) Japan
b) China
c) Nepal
d) Korea

28. Which one of the following famous monuments was built to honour the visit of King George V
and Queen Mary to India?
a) India Gate
b) Victoria Terminus
c) War Memorial
d) The Gateway of India

Situated at Apollo Bunder, The Gateway of India was built to commemorate the visit of King George V and
Queen Mary to Mumbai in 1911. The last British troops to leave India passed through the Gateway in a
ceremony on 28 February 1948.

29. Tulsidas was the author of
a) Ramcharitmanas
b) Adi Garnth
c) Sursagar
d) Bhagavata Purana

30. The study of coins is called
a) Archaeology
b) Historiography
c) Numismatics
d) Epigraphy

– Numismatics is the study of coins.
– Epigraphy is the study of ancient inscriptions
– Archaeology is the scientific study of past cultures and the way people lived based on the things they left behind.
– Historiography is the critical study of the assumptions, principles, and purposes that have informed a historical account

31. Which among the following is NOT a classical Indian dance?
a) Odissi
b) Manipuri
c) Bharatanatym
d) Rasleela
Rasleela closely associated with Sri Krishna is a divine activity played by Sri Krishna along with his gopis.
It is an alluring scene of the festival of Ras (Rasotsav) created by Sri Krishna along with Radha and the other
Gopies on the full moon night in early autumn (Sharad ritu). During Rasleela Lord Krishana stood in
the center surrounded by gopis dancing and singing all around him with full glory. It is said that when Krishna,
Radha and the Gopies danced the Ras Leela, Shiva made sure that no one disturbed the beauty of the
dancing.

32. The colour of potassium flame through double blue glass is
a) green
b) violet
c) crimson red
d) golden yellow

I think Pale Violet would be a better option than Violet here.

33. Precipitation takes place when product of concenteration of ions
a) exceeds the solubility product
b) is less than the solubility product
c) is negligible
d) equals the solubility product

34. Dry ice is
a) Ice dust
b) Liquified Nitrogen
c) Liquified H2
d) Solid CO2

35. Poisoning of drinking water is caused due to presence of
a) Arsenic compound
b) Iron compound
c) Magnesium compound
d) Zinc compound

36. Which institute is known as apex body for development of agriculture?
a) IDBI
b) NABARD
c) IFCI
d) Land Development Bank

37. The duration for which a patent right is valid is known as
a) Patent right
b) Patent life
c) Patent duration
d) Patent time

38. The concept of supply curve as it is used in economic theory is relevant only for the case of
a) Perfect or pure competition
b) Monopolistic competition
c) Oligopoly
d) Monopoly

39. When the prices of two goods tend to vary inversly, they are said to be
a) complements
b) pure goods
c) economic goods
d) substitutes

40. Purchase of cycle by a Household is treated as
a) Savings
b) Consumption
c) Asset creation
d) Capital formation

41. In a Unitary Government, the States derive powers from
a) Parliament
b) Central Government
c) Judiciary
d) Constitution

42. The theory of natural rights was first enunicated by
a) Hugo Grotius
b) Hobbes
c) Rousseau
d) John Locke

43. Individulaism is also known as
a) Laissez-Faire
b) Anarchism
c) Communism
d. Socialism

44. Parlimentary Government is called
a) Non responsible executive
b) Congressional excecutive
c) Cabinet executive
d) Fixed excecutive

45. Fundamental Duties were laid down by
a) 40th Amendment
b) The Original Constituion
c) 42nd Amendment
d) 39th Amendment

The Fundamental Duties were inserted in Article 51A of our Constitution in 1976 by 42nd Amendment Act.

46. Simon Commision was boycotted because
a) it was an all White Commission
b) it did not visit India
c) it was composed of conservatives
d) it was composed of inexperienced men

47. The Nayanars belonged to the
a) Vaishnava cult
b) Shiva cult
c) Jain cult
d) Bhagvath cult

48. Name the Sufi Saint with whom Akbar, the Mughal Emperor, is associated:
a) Shaikh Muinuddin Chishti
b) Shaikh Nizamuddin Auliya
c) Shaikh Salim Chishti
d) Shaikh Farid

Sheikh Salim Chisti of Fatehpur Sikri, a Sufi Saint, was closest and most beloved religious advisor to Akbar.
He blessed Akbar with a son. The birth of Jahangir seemed to fullfill one of Salim Chisti’s prophecies.

49. The Vaisheshika School of Physiscs propounded the atomic theory during the period of
a) Guptas
b) Harsha
c) Ashoka
d) Mauryas

50. Who set up a separate department called the Diwani–Khairat?
a) Akbar
b) Muhammad-bin
c) Firoz Tughlaq
d) Sher Shah

Note : Your feedback/comments are welcome to rectifiy the above post.
I have tried my best to solve the above questions correctly,
but you may assure yourself also.

26 Tips for Solving Errors in English (Part II)

2020-02-12T18:01:00.002+05:30

26 Tips for Solving Errors in English (Part II) :-

After reading first part of this article (26 tips on error spotting), you are now armed with 26 useful tips to Solve spotting errors in English for all competitive exams. Here are 26 rules and you can be confident about tackling any error spotting or phrase replacement question.

Some nouns always use a singular verb.

Eg: Advice, scenery, stationery, mathematics, news

Mathematics are a difficult subject. (Incorrect)
Mathematics is a difficult subject. (Correct)

‘Who’ denotes the subject and ‘whom’ denotes the object.

Whom do you think won the competition? (Incorrect)
Who do you think won the competition? (Correct)
Who did you talk to? ( Incorrect)
Whom did you talk to? ( Correct)

The verb and pronoun in case of two nouns joined by ‘either…or’ or ‘neither… nor’ or by ‘or’ take the form of the latter noun.

Either my father or my sister will use their credit card. (Incorrect)
Either my father or my sister will use her credit card. (Correct)

The verb and pronoun are plural when there is one singular noun and one plural noun and is joined by the conjunction ‘and’.

The teacher and her students donated her money. (Incorrect)
The teacher and her students donated their money. (Correct)

When there are two nouns joined by a preposition like ‘with’ or ‘along with’, the verb and pronoun take the form of the main (first) noun.

Mansi, along with her students, were on their way to the movies. (Incorrect)
Mansi, along with her students, was on her way to the movies. (Correct)

If the plural subject indicates a definite amount or quantity taken as a

whole, it takes the verb in the singular form.

Eighty kilometres are a good distance.( Incorrect)
Eighty kilometres is a good distance. (Correct)

When two or more adjectives show the qualities of the same person or thing, all the adjectives must be in the same degree.

Bhanu is more intelligent and wise than Manu. (Incorrect)
Bhanu is more intelligent and wiser than Manu. (Correct)

When two singular nouns are joined by ‘and’ are preceded by ‘each’ or ‘every’ the pronoun used is singular.

Each man and each boy must be rewarded for their good deeds. ( Incorrect)
Each man and each boy must be rewarded for his good deeds. (Correct)

‘No sooner’ is always followed by ‘than’.

No sooner had the bell rung when the students started leaving the classroom. (Incorrect)
No sooner had the bell rung than the students started leaving the room.( Correct)

‘No sooner’ is always followed by ‘does/do’ or ‘has/have’ in the present tense and by ‘did’ or ‘had’ in the past tense.

No sooner are the boys marching than the whistle blows. (Incorrect)
No sooner do the boys march than the whistle blows.( Correct)

‘A great many’ is always followed by a plural noun and a plural verb.

A great many invention has been declared successful. (Incorrect)
A great many inventions have been declared successful. (Correct)

‘Some’ is used in affirmative sentences to express quantity or degree. ‘Any’ is to be used in negative or interrogative sentences.

I shall buy some books. (Correct)
I shall not buy any books. (Correct)
Have you bought any books? (Correct)

But ‘some’ might be used in interrogative sentences which are requests.

Will you please give me some water? (Correct)

‘Since’ indicates a point of time and ‘for’ stands for the length of time.

He has been reading the book since three hours. (Incorrect)
He has been reading the book for three hours. (Correct)
It has been raining heavily for Monday. (Incorrect)
It has been raining heavily since Monday. (Correct)

When we use ‘everybody’ ‘everyone’, ‘anybody’, and ‘each’ the pronoun of the masculine or the feminine gender is used with respect to the content.

I shall be willing to help each of the girls in her practice. (Correct)

But when the gender is not mentioned, we use the pronoun of the masculine gender.

Anyone can do this job if he tries. (Correct)
Each of the boys in the class has finished their tasks. (Incorrect)
Each of the boys in the class has finished his task. (Correct)

A singular pronoun is used for a collective nouns, and should be in the neuter gender if the collective noun is viewed as a whole.

The pride gave away their location by roaring loudly. (Incorrect)
The pride gave away its location by roaring loudly. (Correct)

When pronouns of different persons are to be used together in a sentence, the sequence of persons should be as follows: second person + third + first person in a normal sentence.

Raju, I and you have finished the work. (Incorrect)
You, Raju and I have finished our studies. (Correct)

‘Older’ refers to persons as well as things and is usually followed by ‘than’.

Raju is elder than all other boys of this class. (Incorrect)
Raju is older than all other boys of this class. (Correct)

‘Elder’ is used for members of the family.

Suyash is my older brother. (Incorrect)
Suyash is my elder brother. (Correct)

‘Than’ is used in the comparative degree usually , but with words like superior, inferior, senior, junior, prior, anterior, posterior and prefer ‘to’ is used.

Gandhi is preferred than Nehru. (Incorrect)
Gandhi is preferred to Nehru. (Correct)

‘Many a’ is always followed by the singular verb.

Many a man were influenced by the speech. (Incorrect)
Many a man was influenced by the speech. (Correct)

The singular verb is used when the subject is “the number of”.

The number of buildings are very low. (Incorrect)
The number of buildings is very low. (Correct)

‘Since’, ‘because’, ‘as’, ‘for ‘are often used alternatively, however there is a difference in their degree. Stronger cases use ‘since’ and ‘because’ and ‘as’ and ‘for’ are used in weak cases.

I respect him as he is the best teacher. (Incorrect)
I respect him because he is the best teacher. (Correct)

A pronoun is sometimes incorrectly used where it is not required at all. Eliminate the redundant ones.

He, being an M.A., he is over qualified for the position. (Incorrect)
He, being an M.A., is over qualified for the position. (Correct)

The relative pronoun ‘that’ is used instead of ‘who’ or ‘which’ after adjectives in the superlative degree.

This is the best which the doctors could do. (Incorrect)
This is the best that the doctors could do. (Correct)

When ‘as if’ is used in the sense of pretension, ‘were’ is used in all cases, even with third person singular.

She behaves as if she was a queen. (Incorrect)
She behaves as if she were a queen. (Correct)

A pronoun takes an objective case after ‘let’.

Let I show it. (Incorrect)
Let me show it. (Correct)

Pronouns joined by ‘and’ are in the same case.

He and me are friends. (Incorrect)
He and I are friends. (Correct)

Both the parts of Error spotting will make you confident enough to answer questions on spotting error . Refer other verbal articles which have been drafted keeping in mind the current Exam pattern.

All the best for your upcoming Xams 👍🏻👍🏻👍🏻👍🏻
Keep visiting our site for more ..
Thnx
And for anything comment below 👎🏻

26 Spotting Errors in English - Check Important Tips & Tricks Here! (pt.-1) :-

2020-02-12T17:09:00.001+05:30

Spotting Errors in English - Check Important Tips & Tricks Here!(Pt.-1):-

Most of you find it difficult to tackle the English Language section. It is comparatively tougher to clear the sectional cut off for English. However, proper guidance and preparation can help you to achieve good marks in this section as well. Spotting Errors in English is one of the important topics. Therefore, we are here to give you General Tips for Spotting Errors in English for various Government SSC ,DMRC, Banking & Other Exams.

Tips & Tricks For Spotting Errors in English

Even those of you who are well-versed with English end up making the silliest of errors in grammar. It is a very natural tendency but error-spotting is not an art that one can’t master. It is just a matter of swearing by some guidelines and practice! Here are 26 tips for error spotting in English:
E.g. Cattle, peasantry, people, clergy, police.
Thus,

The Police has come (Incorrect)
The Police have come (Correct)

2. Certain nouns always take the plural verb because their form is always plural.
E.g. Scissors, trousers, spectacles, thanks, premises.
Thus,

The scissors is kept on the table. (Incorrect)
The scissors are kept on the table. (Correct)

3. When a number is followed by a noun denoting measure, length, money, number or weight, the form of the nouns does not change so long as they are followed by another noun or pronoun.
E.g. Million, pair, metre, year, dozen, foot, head.
Thus,

This is a nine-metres cloth. (Incorrect)
This is a nine-metre cloth. (Correct)

4. When a number is followed by a noun denoting measure, length, money, number or weight, but these are not followed by another noun or pronoun, then they take the plural form.
E.g. Million, pair, metre, year, dozen, foot, head.
Thus,

This sari is nine yard long. (Incorrect)
This sari is nine yards long. (Correct)

5. Certain nouns, especially of the collective category, are used as singular when they specify a unit.
E.g. Public, team, committee, government, audience, orchestra, company, jury.
Thus,

The public were unanimous in their opinion. (Incorrect)
The public was unanimous in its opinion. (Correct)

6. Certain nouns, especially of the collective category, are used in plural when they specify a difference of opinion or class.
E.g. Public, team, committee, government, audience, orchestra, company, jury.
Thus,

The jury was divided in its opinion. (Incorrect)
The jury were divided in their opinion. (Correct)

7. If the pronoun ‘one’ is used, it must be maintained throughout the sentence.
Thus,

One must respect his elders. (Incorrect)
One must respect one’s elders. (Correct)

8. The word ‘whose’is used for living people and ‘which’ is used for non-living things or ideas.
Thus,

Which box is kept on the table? (Incorrect)
Whose box is kept on the table? (Correct)

9. ‘Less’ is used to denote quantity while ‘fewer’ is used to denote number.
Thus,

No less than twenty people were (Incorrect)
No fewer than twenty people were (Correct)

10. ‘One of’is always followed by noun in the plural form.
Thus,

She is one of the least important person in the office. (Incorrect)
She is one of the least important people in the office. (Correct)

11. Only ‘than’ should be used after ‘no other’
Thus,

I like no other movie but Titanic. (Incorrect)
I like no other movie than Titanic. (Correct)

12. After the word ‘Know’, ‘how, ‘what’ or ‘when’ should be used before using the infinitive.
Thus,

I know to speak English. (Incorrect)
I know how to speak English. (Correct)

13. If the verb indicates a purpose, an infinitive must be used and if the verb indicates a cause, a gerund must be used.
Thus,

He went to the mall for watching a movie. (Incorrect)
He went to the mall to watch a movie. (Correct)
He was suspended to show indiscipline. (Incorrect)
He was suspended for showing indiscipline.(Correct)

14. ‘As’ is not used with verbs like ‘appointed’, ‘elected’ , ‘considered’, ‘called’ but it is used with the word ‘regard’.
Thus,

He was elected as Secretary of the organisation. (Incorrect)
He was elected Secretary of the organisation. (Correct)
I regard Sahil my best friend. (Incorrect)
I regard Sahil as my best friend. (Correct)

15. Adverbs should not be confused with adjectives. An adjective describes the characteristic of the subject while an adverb describes the action of the verb.Thus,

The horse looked beautifully. (Incorrect)
The horse looked beautiful. (Correct)

16. Question tags are always the opposite of the sentence which means that if the sentence is positive, the question tag is negative and vice versa.
Thus,

You were dancing, were you? (Incorrect)
You were dancing, weren’t you? (Correct)

17. An infinitive verb should never be split.
Thus,

I request you to kindly tell me. (Incorrect)
I request you kindly to tell me. (Correct)

18. A pronoun after ‘like’, ‘unlike’ and ‘let’ takes an objective case.
Thus,

You will never find a woman like she. (Incorrect)
You will never find a woman like her. (Correct)
Let I do it. (Incorrect)
Let me do it. (Correct)

19. The relative pronoun ‘that’is used instead of ‘who’ or ‘which’ after adjectives in the superlative degree.
Thus,

This is the best which she could do. (Incorrect)
This is the best that she could do. (Correct)

20. To show equality ‘as’ is used both before and after the adjective.
Thus,

I can run as fast, if not faster than you. (Incorrect)
I can run as fast as, if not faster than you. (Correct)

21. Even though more than one’indicates a plural sense, it agrees with a singular noun and takes a singular verb.
Thus,

More than one students completed their project. (Incorrect)
More than one student completed his project. (Correct)

22. ‘Scarcely’and ‘hardly’ are followed by ‘when’ and not by ‘than’.
Thus,

Hardly had the teacher left the room than the pupils started enjoying. (Incorrect)
Hardly had the teacher left the room when the pupils started enjoying. (Correct)

23. ‘Though’ is followed by ‘yet’and not by ‘but’.
Thus,

Though he is poor but he is honest. (Incorrect)
Though he is poor, yet he is honest. (Correct)

24. ‘Lest’must be followed by ‘should’ or by nothing at all and ‘Such’ must be followed by ‘as’.
Thus,

Work hard lest you will fail. (Incorrect)
Work hard lest you should fail. (Correct)
Work hard lest you fail. (Correct)
He is such a writer that everybody should read his books. (Incorrect)
He is such a writer as everybody should read his books. (Correct)

25. ‘Unless’ expresses a condition and is always used in the negative sense. Thus ‘not’ is never used with ‘unless’.
Thus,

Unless you do not work hard, you will not excel in the examination. (Incorrect)
Unless you work hard, you will not excel in the examination. (Correct)

26. ‘When’denotes a general sense and ‘while’ implies a time duration of doing something.
Thus,

When learning how to sing, technique is of utmost importance. (Incorrect)
While learning how to sing, technique is of utmost importance. (Correct)

🙌Click here to go to part 2

Liked this article on Spotting Errors in English? Let us know in the comments section!
Now that you know spotting errors in English, you can now practice some exercises on the same to get a good grip on the topic. Keep looking this Site as we would be coming up with more related articles to make your preparation journey easy.

Completely Explained 📖51 Useful Idioms and Phrases for DMRC Exams - List of Idioms & Phrases Here!

2020-02-12T16:35:00.001+05:30

The English language isn’t as easy as it might seem. Confusing as it may be, strings of random words stitched together are the essence of the language. Here we present you the 51 Useful Idioms and Phrases for DMRC and Bank Exams to boost up your preparation. Read this article and get to know the Top 51 Useful Idioms and Phrases with the meaning & usage in a sentence.

25 Most Expected Idioms & Phrases in Exams :-

Idiom	Meaning
Once in a blue moon	Something that happens very rarely
Use in Sentence – Once in a blue moon, the blue jay can be seen in these parts of the forest.
Beating around the bush	Avoiding the main topic
Use in Sentence – The President was beating around the bush when the citizens demanded a reason for the forgery of legal documents.
Chip on your shoulder	When someone is upset about something that happened a while ago
Use in Sentence – He has a chip on his shoulder for being abandoned by his parents in his childhood.
Cry over spilt milk	Complaining about a loss or failure from the past
Use in Sentence – He was mad because he couldn’t clear the cut off due to a silly mistake. But, then he realized there was no use crying over spilt milk and decided to become more careful.
Spill the beans	To disclose a secret
Use in Sentence – The little one spilled the beans about the surprise vacation we had planned.
Piece of cake	Something that is easy to understand or do
I thought that the problem would be tough, but it turned out to be a piece of cake!
Blessing in disguise	Something good and useful that did not initially seem that way
Use in Sentence – His accident was a blessing in disguise because it gave him a lot of time to think about his life while he was recovering, and as a result, he made some important decisions that improved his life.
Come hell or high water	Possible obstacles in your path (will not stop you)
Use in Sentence – I have decided that come hell or high water I will become an engineer.
Taste of your own medicine	When someone receives the same treatment, usually negative, that he/she gives to others
Use In sentence – She is always taunting others and hurting their sentiments. I just wish someone would give her a taste of her own medicine.
Golden handshake	A big sum of money given to a person when he/she leaves a company or retires
Use in Sentence – The management of the company wanted to decrease their workforce. They offered a golden handshake to their aged employees.
Mean business	Being serious/dedicated
Use in Sentence – The border is sealed by troops who mean business.
Apple of one’s eye	Being cherished more than others are
Use in Sentence – Sam is adored by his teacher for his childlike nature. He is the apple of her eye.
The best of both worlds	The benefits of widely differing situations enjoyed at the same time.
Use in Sentence – I had the best of both worlds since I worked as an ordinary member of the team but got to learn from the leaders.
Feeling a bit under the weather	Feeling slightly ill
Use in Sentence – I may not be able to jog today, as I am feeling a bit under the weather.
Icing on the cake	Something that turns good into great
Use in Sentence – India’s victory over England on India’s Independence Day was like icing on the cake.
Cost an arm and a leg	Be very expensive
Use in Sentence – His laziness made him miss his flight to Chandigarh. The next ticket cost him an arm and a leg.
Jump the bandwagon	To join a popular activity or trend
Use in Sentence – When he was detected with diabetes, he quickly jumped on the bandwagon and joined the Zumba dance class.
Ball is in your court	When it is up to you to make the next decision or step.
Use in Sentence – Now the ball is in your court; decide whether you want to reply or not.
Bite off more than you can chew	To take up a task which you may not be able to accomplish due to lack of ability.
Use in Sentence – I bit off more than I could chew when I decided to take up the 300-page research project.
Can’t judge a book by its cover	Cannot judge something primarily on appearance.
Use in Sentence – The house looked impressive in the advertisement. Still, I made a trip to the house to check everything. It is wise not to judge a book by its cover.
Hear it on grapevine	To hear rumors about something or someone
Use in Sentence – I heard it on grapevine that he had stiffed an old man asking for his pension.
It takes two to tango	Actions or communications need more than one person
Use in Sentence – Even though I thought I would be fired after the altercation with my manager, thankfully upper management realized that it takes two to tango.
Last straw	The final problem in a series of problems
Use in Sentence – My body was already in bad shape. The accident was the last straw. I am now on complete bed rest.
To be in the doldrums	To be in low spirits
Use in Sentence – Sam was in the doldrums after he was insulted by the boss in front of his colleagues.
To sit on the fence	To remain neutral
Use in Sentence – Since I wasn’t aware of the details, I decided to sit on the fence during the argument between my cousins.

Other Useful Idioms & Phrases

Idiom	Meaning
Break the ice	To initiate a social conversation or interaction
Use in Sentence – At the start of the lecture, the new professor tried to break the ice by telling a joke.
A bird’s eye view	A view from a very high place that allows you to see a very large area
Use in Sentence – The Singapore Big Wheel offers a bird’s eye view of the city.
A litmus test	A method that helps to know if something is correct
Use in Sentence – Taking up the job served as a litmus test for me to know how good I was at applying my knowledge.
At the drop of a hat	Willingness to do something instantly
Use in Sentence – She expects me to make dinner at the drop of a hat even if I am very busy with office work.
Afraid of one’s own shadow	To become easily frightened
Use in Sentence – Her creepy encounter with the supernatural had a devastating effect on her. She is now afraid of her own shadow.
A house of cards	A poor plan
The State’s new scheme was initially welcomed, but later turned out to be a house of cards when it was discovered how easy it was to perpetrate a scam.
Black and blue	Full of bruises
Use in Sentence – The young lad was all black and blue after a tiff with a raging senior.
Be on cloud nine	Be very happy
Use In Sentence – I will be on cloud nine when my first article gets published.
Bone of contention	A subject or issue over which there is continuing disagreement
Use in Sentence – The examination system has long been a serious bone of contention in the HRD Ministry.
Eat humble pie	To apologize humbly
Use in Sentence – He will have to eat humble pie for the disrespect shown to the Captain
Fool’s paradise	A false sense of happiness or success
Use in Sentence – They were living in a fool’s paradise, refusing to accept that they were facing poverty.
Give cold shoulder	To ignore
Use in Sentence – I sent her a message to apologize for my misbehavior, but she gave me the cold shoulder.
Get a raw deal	To not be treated as well as other people
Use in Sentence – The fact is that students in government schools get a raw deal.
Hit the nail on the head	To do the correct thing
Use in Sentence – She hit the nail on the head when she laid out a list of justifiable grievances she had with the company.
Hand to mouth	live on only basic necessities
Use in Sentence – The severe drought led the farmers to live hand to mouth.
Hit the bull’s eye	To be exactly right about something or achieve the best result possible.
Use in Sentence – The detective hit the bull’s eye when he figured out that nobody but the doctor could have had access to the poison.
Let the cat out of the bag	To reveal the secret carelessly or by mistake
Use in Sentence – Now that she had let the cat out of the bag, she had no option but to confess.
Make a face	To show dislike or disappointment through facial expressions
Use in Sentence – Little Stella made a face at the sight of bitter gourd in her food.
Open Pandora’s Box	To find a source of great troubles and problems
Use in Sentence – Finding the wallet on the road opened up a Pandora’s box. I was arrested for stealing when I went to report it at the police station.
It’s Greek to me	Something that is not understandable
Use in Sentence – I failed my commerce test; it was all Greek to me!
Don’t put all your eggs in one basket	Do not put all your resources in one basket.
Use in Sentence – The boy put all his money into his dream startup that eventually failed. I had told him not to put all his eggs in one basket.
To call a spade a spade	To be brutally frank, outspoken, blunt in speech.
Use in Sentence – Let’s call a spade a spade – popular he may be, but that man is a liar.
To be a Good Samaritan	To be kind and compassionate to someone in distress
Use in Sentence – I was sure I would be stuck on the highway till the morning, but a Good Samaritan offered me a ride home.
To put in a nutshell	To say in a few words or to make something concise
Use in Sentence – The Textbook Development Committee decided to put the 30-page chapter, in a nutshell, to help save time for students during revision.
To pour oil on troubled waters	To make peace
Use in Sentence – I am always stuck pouring oil on troubled waters when my mother and wife start their bickering.
To move heaven and earth	To exert all efforts
Use in Sentence – He moved heaven and earth to ensure that his family was taken care of in the foreign land in his absence.

Now remember them and All the best for your upcoming Exams 👍🏻🤗

DMRC PREVIOUS YEAR QUESTION

2020-02-06T08:33:00.001+05:30

Hello everyone ..

In this post we are providing DMRC JE 2018 QUESTIONS WHICH CAN HELP U SECURE MORE MARKS IN THE UPCOMING EXAM.

If image is not clear than Click on image or Switch to web version 💻

PDF download link 👎🏼:-

DMRC 2018 QUESTION

GK - First in India (male)

2020-02-06T02:22:00.001+05:30

“First Male Personalities of India”. This is an important topic of General Awareness for the upcoming Railways NTPC, GROUP D & SSC 2019 Exams. These questions will help you prepare efficiently for the upcoming examinations.

Railways Static GK: First in India

First Person (Male)	NAME	OTHER IMPORTANT FACTS
First President of Indian Republic	Dr. Rajendra Prasad, 1950 to 1962	President of the Constituent Assembly (1948-1950)
First Prime Minister of free India	Pt. Jawahar Lal Nehru	He is also known as the architect of modern India. Chairman of the constituent assembly. Chairman of Union Constitution Committee, Union Powers Committee and States Committee
First Indian to win Nobel Prize	Rabindranath Tagore	Also Known as Gurudev. Wrote National Anthem of India.
First President of Indian National Congress	W.C. Banerjee
First Muslim President of Indian National Congress	Badruddin Tayyabji
First Muslim President of India	Dr. Zakir Hussain
First British Governor General of India	Lord William Bentinck (1833-1835)	Sati system was banned during his regime.
First British Governor General of Bengal	Lord Warren Hasting (1773-1785)	First Maratha war and second Mysore war occured during his regime Founded Asiatic Society of Bengal.
First British Viceroy of India	Lord Canning	Revolt of 1857 happened during his regime. Established 3 universities at Calcutta, Madras and Bombay.
First Governor General of free India	Lord Mountbatten	Indian Independence Bill 1947 was passed during his regime.
First and the last Indian to be Governor General of free India	C. Rajgopalachari	Informally called as Rajaji or C.R.
The first man who introduced printing press in India	James Hickey (Bengal Gazette)	Bible was the first book printed in India.
The First Indian to join the I.C.S	Satyendra Nath Tagore
First man in Space from India	Rakesh Sharma
First Prime Minister of India who resigned without completing the full term	Morarji Desai
First Indian Commander-in-Chief of India	General Cariappa
First Chief of Army Staff	Gen. Maharaj Rajendra Singhji
First Indian to join Viceroy’s executive council	S.P.Sinha
First President of India who died while in office	Dr. Zakir Hussain	He was awarded Bharat Ratna award.
First Muslim President of Indian Republic	Dr. Zakir Hussain
First Prime Minister of India who did not face the Parliament	Charan Singh	Serving from 28 July 1979 until 14 January 1980.
First Field Marshal of India	S.H.F. Manekshaw(1914-2008)
First person to get Nobel Prize in Physics from India	C.V.Raman	For the discovery of Raman Effect or Raman Scattering.
First Indian to receive Bharat Ratna award	C. Rajgopalachari, Dr. Radhakrishnan & CV Raman	First and the last Indian to be Governor General of free India First Vice President of India: Dr. Radhakrishnan Nobel Prize Winner: CV Raman
First Indian to cross English Channel	Mihir Sen
First Person to receive Jnanpith award	Sri Shankar Kurup
The first Speaker of the Lok Sabha	Ganesh Vasudeva Mavalankar	Also known as Dadasaheb Speaker of the Constituent Assembly of India
First Vice-President of India	Dr. Radhakrishnan
First Education Minister	Maulana Abul Kalam Azad
First Home Minister of India	Sardar Vallabh Bhai Patel	India's first Deputy Prime Minister. Started Bardoli Satyagarh. Chairman of Provincial Constitution Committee and Advisory Committee on Fundamental Rights, Minorities and Tribal and Excluded Areas.
First Indian Air Marshal	S. Mukherjee
First Indian Naval Chief	Vice Admiral R.D. Katari
First Indian Judge of International Court of Justice	Dr. Nagendra Singh
First person to reach Mt. Everest without oxygen	Sherpa Dorjee
First person to get Param Vir Chakra	Major Somnath Sharma
First Chief Election Commissioner	Sukumar Sen
First person to receive Magsaysay Award	Acharya Vinoba Bhave	First person chosen for Individual Satyagraha.
First person of Indian origin to receive Nobel Prize in Medicine	Hargovind Khurana
First Chinese traveller to visit India	Fahein	Visited India during the reign of Gupta emperor Chandragupta II
First person to receive Stalin Prize	Saifuddin Kitchlu	Jalliawala Bagh gathering 1919 was held against the arrest of Dr. Saifuddin Kitchlu and Dr. Satyapal.
The first person to resign from the Central Cabinet	Shyama Prasad Mukherjee	Served as Minister for Industry and Supply in Prime Minister Jawaharlal Nehru's cabinet Founded the Bharatiya Jana Sangh, a predecessor to the Bharatiya Janata Party (BJP), in 1951.
First person to receive Nobel Prize in Economics	Amartya Sen	For his contributions to welfare economics
First Chief Justice of Supreme Court	Justice Hirala J. Kania
First Indian Pilot	J.R.D. Tata (1929)

Chemistry Notes - synthetic material and chemicals

2020-02-06T02:15:00.001+05:30

In this article, we will discuss some synthetic material and chemicals that are used in everyday life e.g. cement, dye, and fertilizer. This topic is important as per competitive exam perspective.

Synthetic Materials:

Material created by man using natural materials is known as synthetic materials. Some important synthetic materials are given below:

Cement:

Discovered by English Mason, Joseph Aspdin, he named it Portland cement.
Limestone, clay, and gypsum are some important raw material that is required in the manufacturing of the cement.
When cement is mixed with water and left for some time, it becomes a hard mass. This is known as the setting of Cement, it is an exothermic process that’s why sprinkling of water is done for a few days for new construction.
Mortar is a mixture of cement, sand, and water; it is used for plastering walls and binding bricks.
Concrete is a mixture of cement, sand, gravel, and water. It is used for the construction of floors.
The structure having iron rods embedded in wet concrete is known as reinforced concrete.

Glass:

It is a supercooled liquid of silicate, it is amorphous in nature.
The raw material used for the formation of glass is sodium carbonate, calcium carbonate, and sand.
Sudden cooling of molten glass makes it brittle if cooled very slowly make it opaque.
The process of slow and uniform cooling is called annealing.
When a glass is attacked by hydrofluoric acid, it is called etching of glass.
Coloured glass is obtained by adding certain metallic oxides or salts to the molten glass.

Types of glasses and their uses

Soft glass (Soda Glass):

The mixture of sodium or calcium silicate.
Used in making of glass, mirrors, and common glassware, etc.

Hard Glass:

The mixture of potassium and calcium silicates.
Resistant to the action of acids and used for making hard glass.

Pyrex glass (Borosilicate glass) :

Used by fusing a mixture of sand, lime, borax and alkali carbonates.
Used in making of pharmaceuticals containers.

Glass fibre:

Glass wool is an excellent heat insulator.
Used in the insulating material in oven, refrigerator.

Chemicals Used in Agriculture:

Fertilizers:

These are the chemical substances which are rich in a particular nutrient.
They supply nitrogen phosphorus and potassium.
Excess used of fertilizers can reduce the fertility of the soil.
Good fertilizers are easily dissolved in water and stable so that elements are retained for a longer duration.
It should not disturb the pH level of the soil.
Urea is the best fertilizers.
Calcium superphosphate, nitro phosphate, triple phosphate and phosphatic slag (Thomas slag) are some important phosphatic fertilizers.
The mixture of nitrogenous, phosphatic and potash fertilizers in the proper ration is called NPK fertilizers.
NP fertilizers are prepared by mixing nitrogenous and phosphatic fertilizers in a definite ratio.

Pesticides:

Pesticides are the chemicals which are used to kill pests which adversely affect the crops e.g. DDT and malathion. They can be categorized into the following category:

Insecticides
Fungicides
Nematicides
Molluscicides
Herbicides
Rodenticides: Zinc phosphide is used to kill rodents.

Explosives

These are the substance which contains a great amount of stored energy that can produce an explosion.
Chemical explosives may consist of either a chemically pure compound such as nitroglycerine or a mixture of a fuel and an oxidizer.

Types of Explosives:

Primary Explosives:

A relatively small amount of energy is required for initiation.
Use in detonators e.g. acetone peroxide, silver azide and ammonium permanganate.

Secondary Explosives:

Are less sensitive and require more energy for initiation.
RDX and TNT are some secondary explosives.

Tertiary Explosives:

Used in large scale mining and construction operation and in terrorism.
Nitro-glycerine is a highly unstable and sensitive liquid also called Noble’s Oil.
Dynamite is a mixture of highly sensitive nitro-glycerine with sawdust, powdered silica.
RDX (Research and development explosive) is a very powerful explosive.

Dyes:

Coloured substances used for colouring wool, textiles materials, and foodstuffs.
A material which is used as dyes must be able to fix itself to the material it is applied and must resist the action of water, acids, and alkalies.

Dyes can be classified into the following category:

Azo Dyes:

These dyes contain the azo group (-N=N-).
Formed during the coupling reactions, e.g. red, orange.

Indigoid Dyes:

These dyes contain indigoid group in their molecules e.g. indigo.

Anthraquinone dyes

Phthalein Dyes

On the basis of their applications dyes can be classified into the following types:

Vat Dyes: these dyes are water-insoluble dyes and applied to fibre cotton and are obtained from indigo dyes.

Direct Dyes: these dyes can be applied to the fabric from their aqueous solution.

Acid dyes: used as their sodium salts which are soluble in water.

Basic dyes: In acidic medium, these dyes are used to dye modified nylons and polyesters e.g. aniline yellow and malachite green.

Biology Shortnotes - Sex determination in human beings

2020-02-06T02:00:00.001+05:30

In this article, we will discuss the sex determination in human beings. This is an important topic in biology and questions are frequently asked from this topic.

हिंदी में पढ़ने के लिए निर्देशों का पालन करें: -
1. Click to view web version
2. Slide down & click on translate
3. Choose Hindi

Sex Determination:

In a human being, we determine the sex with the help of the sex chromosome i.e. with the help of X and Y chromosome.
In a human being, 46 chromosomes are found out of which 44 are found in 22 pairs called autosomes and the other two chromosomes are called sex chromosomes.
The rest two chromosomes are the same in females and are called X- chromosomes (XX).
In a male, the rest two chromosomes are different and are called X and Y chromosomes.
During reproduction females produce one type of gametes and containing 22 autosomes and one X chromosomes, while males produce two types of gametes one have 22 + X type chromosomes and others have 22+ Y types of chromosomes.
When male gametes i.e. sperm carrying X chromosomes fertilizes an ova, the zygote develops into a female.
When a sperm carrying Y chromosomes fertilizes an egg, Zygote develops into a male.

Some Genetic Disorder occurs due to Chromosomes:

Klinefelter Syndrome:

When a male has an extra X or Y chromosome in sex chromosomes then the condition will be XXY or XYY instead of XY. The individual became sterile in this condition.
In female when an extra X chromosome is present instead of XY they show normal development but limited fertility, metal retardness is also seen in this type of syndrome.

Turner’s Syndrome:

When female has single-sex chromosome (X0) their ovaries are rudimentary, lack of secondary sexual characteristics.

Down’s Syndrome:

When an extra chromosome is added to 21^st autosomal chromosomes this lead to develop Down’s syndrome.

Colour Blindness:

This disorder leads to failure to distinguish between red & green colour.
The gene responsible for this disease is situated on sex chromosomes.

Patau’s Syndrome:

This type of syndrome is developed by addition of autosomal chromosome in 13^th chromosome.
There is a cut mark in the lip and the person is mentally retarded.

Number of Chromosomes in Different Organisms:

S. No.	Organisms	No. of Chromosomes
1.	Pigeon	80
2.	Dog	78
3.	Horse	64
4.	Chimpanzee	48
5.	Human	46
6.	Rabbit	44
7.	Cat	38
8.	Frog	26
9.	Pea	14
10.	Tomato	24
11.	Wheat	42
12.	Potato	48

GK notes - Various disease & Associated parts of human body

2020-02-06T01:58:00.001+05:30

Diseases and Associated Part of Human Body is a very important topic for any competitive exam. Around 2 questions are asked about this topic in SSC Exams. Make sure you go through these notes and learn them by heart. They are going to be really helpful for your upcoming exams.

Parts of the Body Affected by Diseases

Disease	Affected Body Part
Arthritis	Joints
Asthma	Bronchial Muscles
Cataract	Eyes
Diabetes	Pancreas
Diphtheria	Throat
Eczema	Skin
Glaucoma	Eyes
Goitre	Thyroid Gland
Jaundice	Liver
Leukemia	Blood
Malaria	Spleen
Meningitis	Brain and Spinal Cord
Otitis	Ears
Paralysis	Nerves
Pneumonia	Lungs
Polio	Legs
Pyorrhoea	Teeth and Gums
Rheumatism	Joints
Sinusitis	Inflammation of sinus linings
Tonsillitis	Tonsils
Trachoma	Eyes
Tuberculosis	Lungs
Typhoid	Intestines

Diseases and Causative Agents

Causative Agent	Disease
Bacteria	Diphtheria, Gonorrhoea, Meningitis, Cholera, Leprosy, Typhoid, Tetanus, Tuberculosis, Plague, Whooping Cough, Pneumonia
Virus	Chicken Pox, Small Pox, Measle, Mumps, AIDS, Yellow fever, Influenza, Dengue fever, Rabies, Polio-meritis phelebotomus
Protozoans	Malaria, Sleeping sickness, Kala-azar, Leishmaniasis, Amoebic dysentery
Fungus	Athlete's foot, Ringworms, Madura foot, Dhobi's itch
Helminths	Filaria, Tapeworm and Hookworm transmission

Important Information about Human Body

Biggest Organ: Liver
Heart Beat: 72 times in a minute
Master Gland: Pituitary
Number of Bone: 206
Number of Muscles: 640
Number of chromosomes: 46 or 23 pairs
Normal Blood Pressure: 80 to 120
Teeth: 32
Volume of Blood: About 7 litres in normal body or about 7% of the total body weight.
Largest; Part of human Brain: Cerebrum

All the best!

Biology - Miscellaneous Short Notes

2020-02-06T01:55:00.001+05:30

In this post, we are providing you with the notes on DNA, RNA, Virus, and Bacteria. Questions from these topics are frequently asked in the Railways & SSC Exam.

Deoxyribonucleic Acid (DNA) :

DNA stands for Deoxyribonucleic Acid, it was discovered by Frederic Mischer.
DNA is a double-stranded molecule made up of an elongated chain of sub-units called nucleotides.
DNA is mainly found in the nucleus and in small amount it is also found in mitochondria an chloroplast.
Chemically a nucleotide has three components.

(1) Nitrogenous base

(2) Pentose Sugar

(3) Phosphate group.

The nitrogenous base is of two types i.e.Purine & Pyrimidines.
Purines contain two nitrogen base i.e. Adenine and Guanine.
Pyrimidine nitrogen bases are Thymine and Cytosine, thus there are four kinds of nucleotide present in DNA i.e. Adenine, Guanine, Thymine, Cytosine.

Structure of DNA:

Watson and Crick give the structural model of DN
DNA molecule is consists of two polynucleotide strand, forming a double helix structure.
Each strand has a backbone of sugar and phosphate, nitrogen base is attached to the sugar.
Two strands are joined together by hydrogen bonds between the bases.
Adenine pairs with thymine whereas guanine pairs with cytosine.
Adenine and thymine are complementary to each other and cytosine is complementary to guanine.

Functions of DNA:

DNA is genetic material and contains genetic information in coded form.
DNA has two main function replication and expression.

2.Ribonucleic Acid (RNA) :

RNA stands for Ribonucleic acid.
RNA is single-stranded nucleic acid made up of phosphate, a ribose sugar and nitrogen base uracil, adenine, guanine, and cytosine.
It is found in the nucleus as well as cytoplasm.
Its main function is to synthesise the protein.
RNA is of three kinds.

1.Messenger RNA (mRNA): It brings the message from DNA found in the nucleus to cytoplasm in the coded form.

2.Ribosomal RNA (rRNA): Present in ribosome which is the site of protein synthesis.

3.Transfer RNA (t RNA): It is the carrier of amino acid and transfers it to the ribosome.

Difference between RNA and DNA

3.Virus:

Virus was discovered by Russian Scientist Iavanosky during the test of Mosaic disease in Tobacco.
Virus acts as a link between the living and non-living.
Virus is dead but when it comes in contact with the living cell it gets activated.
‘The virus in which RNA is found as the genetic material is called Retrovirus.
Virus is of three types:

Plant Virus: RNA is present as its nucleic acid
Animal Cell: DNA and sometimes RNA is found in it.
Bacteriophage: They kill the bacteria e.g. T-2 phage.

4.Bacteria:

Bacteria was discovered by Antonie van Leeuwenhoek and its study is known as bacteriology.
Bacteria is of different types on the basis of shape:

Bacillus: This is a rod-like or cylindrical.
Round or Cocus: These are round and smallest bacteria.
Comma shape or vibrio
Spirillum: Spring or Screw shaped.

Anabaena and Nostoc cyanobacteria fixed the atmospheric nitrogen into the soil.

Chemistry notes - Atomic Models & Quantum Numbers

2020-02-06T01:52:00.001+05:30

In this article, we will discuss atomic models and quantum numbers. This topic is important as per the exam point of view. Questions were frequently asked about this topic.

Atomic Models:

To show the arrangement of fundamental particles in an atom various models were proposed, some important models are as follows:

Dalton’s Atomic Theory:

The different assumptions of this theory are as follows;

All matters are made up of atoms which are indivisible and indestructible.
All the atoms of a given element have identical properties including identical mass.
Atoms combine in small whole numbers to form the compound.
Chemical reactions involve only combination, separation or rearrangement of atoms.

Thomson’s Atomic Model:

Every atom consists of uniformly positively charge sphere having the radius in the order of 10^-10m in which entire mass is uniformly distributed and negatively charges electrons are embedded randomly.
Thomson uses the cathode ray tube to gives its atomic model.
This model is known as the plum pudding model.
According to him, negative charge particles are distributed in the atom and to balance this negative charge some positive charge particles also present in it.
The atom as a whole is neutral.

Drawbacks of Thomson’s Atomic Model:

It could not explain the origin of spectral series of hydrogen and other atoms.
It could not explain large angle scattering of alpha particles.

Rutherford’s Atomic Model:

He fired a beam of the alpha particle on a sheet of gold to gives its model theory.
The existence of nucleus was proved by Rutherford in his alpha particle scattering experiment.
The entire positive charge and almost entire mass of the atom is concentrated at its centre in a very tiny region of the order of 10^-15m, called the nucleus.
The negatively charged electrons revolve around the nucleus in different orbits.
The total positive charge on the nucleus is equal to the total negative charge on electron; therefore atom as overall is neutral.
A nucleus consists of positively charged protons and electrically neutral neutrons.

Limitations of Rutherford’s Atomic models:

According to Maxwell electromagnetic wave theory, an accelerated charged particle emits its energy in the form of electromagnetic waves. Therefore an electron must emit emits energy during its course of accelerated motion around the nucleus. Due to which the radius of its path will decrease gradually and ultimately it will fall in the nucleus.

Plank’s Quantum Theory:

Planck gave a new revolutionary theory of radiation known as the quantum theory of radiation.

According to this theory

Radiant energy is not emitted or absorbed continuously but discontinuously in the form of small packets of energy known as photons (quanta).

The amount of energy associated with a quantum of radiation is proportional to the frequency of radiation.

Energy = hν

Where h is Planck’s constant

Bohr’s Model:

Bohr’s model is based on the quantum physics i.e. quantization of energy
This model is similar to the planetary model in which electron revolves around the nucleus in the specific orbit
Bohr’s model is considered as the primitive hydrogen atom model
Every orbit has a specific size and energy level.
Smallest energy is found in the smallest orbit as energy is related to the size of the orbit.
Electrons can move from one orbit to another by emitting or absorbing energies according to quantum mechanisms.

Heisenberg’s Uncertainty Principle:

According to this theory, the position and velocity or momentum cannot be measured at a single instant.
Heisenberg principle is not applicable to macroscopic objects

De-Broglie Concept:

De Broglie states that electron has dual nature i.e. wave nature and particle nature
Wavelength (l) of an electron is inversely proportional to its momentum (p)

l=h/p=h/mv, where h is Planck’s constant

Shell:

The electron has a definite energy characteristic of the orbit in which it is moving. These orbit or energy levels or shells therefore also known as stationary orbits.

n=1,2,3,4

Shell =K,L,M,N

The shell with n=1 is closest to the nucleus and an electron in this level has the lowest energy as it is closest to the positive charge of the nucleus.

Distribution of electrons in different orbits:

It was suggested by Bohr and Burry and rules that govern it are as follows:
The maximum number of electrons present in a shell is given by the formula 2n² where n=1,2,3 and 4 for K, L, M and N shells respectively.
The maximum number of electrons that can be accommodated in the outermost orbit is 8.
The shells are filled in a step-wise manner.

Electronic Configuration:

It is the arrangement of electrons in various shells, subshells and orbitals in an atom.
It is written as 2,8,8,18,32
The maximum number of electron in a shell is given by 2n²

Filling or orbitals in Atoms:

The filling of electrons into orbitals of different atoms takes place according to the Aufbau Principle, Pauli Exclusion Principle and Hund’s rule of maximum multiplicity.

According to Aufbau principle in the ground state of an atom, electron enters the orbital of lowest energy first and subsequent electrons enter in the order of increasing energies.

Lower the value of (n+l) for an orbital, lower is its energy.

here l is the azimuthal quantum number and n indicates the principle quantum number

If two orbitals which have same (n+l) value, the orbital with the lower value of n has lower energy.

Hund’s rule of maximum multiplicity deals with the filling of electrons into the orbitals belonging to the same sub-shell. According to this rule, electron pairing will not take place in orbital of same energy until each orbital is first singly filled with parallel spin.

Quantum Numbers:

Each electron in an atom is characterised by a set of definite values of three quantum numbers n, l and m. In addition of these three numbers, fourth quantum numbers is also needed which specifies the spin of the electron.

Principal quantum number (n):

Determines the main energy level of the shell in which the electron is present.

The various values of n are 1, 2, 3 and 4 etc. also known as K, L, M and N etc. respectively, as the value of n increases energy of electron also increases.

Azimuthal quantum number (l) determines the sub-level or sub-shell(s, p, d and f) in a given principal energy level or shell to which an electron belongs.

Magnetic quantum number (m) gives the information about the orientation of the orbitals.

Spin quantum number(s) describe the spin orientation of the electron; the electron can spin only in two ways, i.e. clockwise or anticlockwise.

Pauli Exclusion Principle:

It states that no two electrons in an atom can have the same set of four quantum numbers.

Chemistry - Important Chemical compounds and their uses

2020-02-06T01:49:00.001+05:30

In this article, we will share some important chemical compounds which are useful for the upcoming Railways , SSC & other Exams. In this list Compound name, Chemical formula of the compound and its uses are given.

Here is the list of Chemical Compounds

1. Calcium Carbonate

Formula: CaCO₃

Uses: Non-prescription drug for relief from acid indigestion and heartburn. Also considered a calcium supplement..

2. Sodium Chloride

Formula: NaCl

Uses: Used to season food (during food preparation and at the table), also used in the past as a method of food preservation.

3. Methane

Formula: CH₄

Uses: natural gas, fuel (also called Marsh Gas)

4. Aspirin

Formula: C₉H₈O₄

Uses: Pain Reliever

5. Potassium Tartrate

Formula: K₂C₄H₄O₆

Uses: cream of tartar, cooking

6. Baking soda

Formula: NaHCO₃

Uses: cooking

7. Acetaminophen

Formula: C₈H₉NO₂

Uses: Pain Reliever

8. Acetic Acid

Formula: C₂H₄O₂

Uses: Active ingredient in vinegar

9. Caffeine

Formula: C₈H₁₀N₄O₂

Uses: stimulant in coffee, tea, some soda

10. Propane

Formula: C₃H₈

Uses: fuel for cooking

11. Sodium Carbonate

Formula: Na₂CO₃

Uses: washing soda

12.Phosphoric Acid

Formula: H₃PO₄

Uses: flavouring in soda

13. Ascorbic acid

Formula: C₆H₈O₆

Uses: Essential vitamin (vitamin C)

14. Ammonia

Formula: NH₃

Uses: fertilizer, household cleaner when dissolved in water

15. Ethylene Glycol

Formula: C₂H₆O₂

Uses: antifreeze

16. Calcium Carbonate

Formula: CaCO₃

Uses: antacid

17. Ethanol

Formula: C₂H₅OH

Uses: disinfectant, alcoholic beverages

18.Carbon dioxide

Formula: CO₂

Uses: carbonating agent in soda

19. Hydrochloric Acid

Formula: HCl

Uses: production of batteries, photoflash bulbs and fireworks. It's even used to process sugar and make gelatin.

20. Calcium Oxide

Formula: CaO

Uses: Less common in modern homes than in the past. Glows when heated; was used in theatres before invention of electric lighting. Health risks on skin contact or inhalation.

21. Sucrose

Formula: C₁₂H₂₂O₁₁

Uses: Used in cooking. Use as a sweetener.

22. Potassium Carbonate

Formula: K₂CO₃

Uses: Potash is the common name for various mined and manufactured salts that contain potassium in water-soluble form.

23. Plaster of Paris

Formula: CaSO₄·1⁄2H₂O

Uses: used for casts to hold broken limbs in place, modelling casts, sculptures and in plasterboard walls and ceilings

24. Gypsum

Formula: CaSO₄^.2H₂O

Uses: Use to manufacture dry wall, plaster, joint compound.

25. Sodium Bicarbonate

Formula: NaHCO₃

Uses: Used in baking where it reacts with other ingredients, releasing carbon dioxide (CO2), helping dough rise.

26. Sulphuric Acid

Formula: H₂SO₄

Uses: Used in lead-acid batteries for cars and other vehicles. It is also known as Vitriol.

27. Hydrogen Peroxide

Formula: H₂O₂

Uses: Used as a mouth wash (Personal Hygiene)

Chemical formula of Psuedo Alum - K₂SO₄.Al₂(SO₄)₃.24H₂O
Aqua Regia is a mixture of - HCl and HNO₃ . In aqua-regia,3 parts of HCl and 1 part of HNO₃ are mixed.

Chemistry - Important Metals and their uses

2020-02-06T01:45:00.001+05:30

This article covers all the important question related to metals.

Metals:

Metals are good conductors of heat & electricity and are malleable and ductile.
Gold and silver are the most malleable and best ductile metals.
Silver is the best conductor of heat followed by copper.
Aluminium and copper are good conductors of heat that’s why cooking utensils are made of them.
Mercury offers high resistance to the flow of electric current.
Sodium and potassium are so soft that they can be easily cut with a knife.
Metals are electropositive in nature.
Almost all the metal oxides are basic in nature but zinc oxide and aluminium oxide are amphoteric.

Alkali metals and their compounds

Metals of the first group are alkali metals.
This group lies in the s-block of the periodic table of elements as all alkali metals have their outermost electron in an s-orbital.
Lithium, sodium, potassium, rubidium and cesium are alkali metals.
These metals are stored under kerosene or liquid paraffin’s to protect them from the action of air.

Sodium chloride (NaCl):

Commonly known as table salt
Used in the manufacturing of sodium hydroxide and chlorine gas.
It is used as a starting material in the manufacturing of caustic soda.
It is used in the removing of ice from the road, now a- days CaCl₂ and MgCl₂are also used for this purpose.

Sodium hydroxide (NaOH):

Used in the refining of bauxite material.
Used in soap, dyes and artificial industries.

Sodium bicarbonate (NaHCO₃):

It is commonly known as baking soda.
Used for wool washing.
Used in the fire extinguisher.

Sodium carbonate (Na₂CO₃)

It is commonly known as washing soda.
Used for softening of hard water.
The mixture of sodium carbonate and potassium carbonate is known as Fusion mixture.

Sodium Sulphate:

It is commonly known as Glauber’s salt.
It is used as a purgative.

Sodium thiosulphate:

It is commonly known as Hypo and used in photography as a fixing agent.

Potassium carbonate:

It is known as pearl ash.

Potassium hydroxide:

Commonly known as caustic potash.
Use in the preparation of soft soap.
Its aqueous solution is known as potash Lye.

Potassium superoxide.

Used in space capsules, submarines, and a breathing mask as it removes in carbon dioxide and carbon monoxide.

Alkaline Earth Metals and their compounds

The alkaline earth metals are six elements in column (group) 2 of the Periodic table.

They are beryllium (Be),magnesium(Mg),calcium (Ca), strontium (Sr),barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metal at the same temperature and pressure.

Mg(OH₂) is known as milk of magnesia and use as an antacid.

Calcium oxide

It is also known as quick lime.
Used in the manufacturing of calcium chloride, cement, and bleaching powder.

Calcium sulphate (CaSO4):

The compound exists in three levels of hydration:

anhydrous state (mineral name: "anhydrite") with the formula CaSO₄
dihydrate (mineral name: "gypsum") with the formula CaSO₄(H₂O)₂.
hemihydrate with the formula CaSO₄(H₂O)_0.5
It loses a part of water to form plaster of Paris.
Plaster of Paris is a white powder which becomes hard on contact with water and is used in the manufacturing of statues.

Some Important Metals & Their Uses

Aluminium (Al):

Ore of aluminium is bauxite.
It is the third most abundant element in the earth’s crust.
Used in the manufacturing of cooking utensils.
Ammonal, a mixture of aluminium powder and ammonium nitrate is used as an explosive.

Tin:

The ore of tin is Cassiterite.
The process of converting white tin to grey tin is known as tin disease or tin plague.
Used in the plating of iron to protect the iron from rusting.
Tin amalgam is used in the manufacturing of mirrors.

Lead(Pb)

The main ore of lead is galena.
Use in the preparation of sulphuric acid through the chamber process.
Lead acetate is known as sugar of lead.

Zinc(Zn):

It is used in the galvanization process to prevent the rusting of iron.
Zinc sulphide is used in the preparation of X-ray screens.
Zinc oxide is known as philosopher wool.

Mercury(Hg):

It is the only metal which is liquid at room temperature.
It forms alloys with all other metal except iron and platinum.

Nickel(Ni):

Silvery white soft metal.
Used as an anode in Edison batteries.

Iron(Fe)

Extracted from the haematite ore and do not occur in Free State due to its reactivity.
Ferric chloride is used as a styptic to stop bleeding from the cut.
Ferrous sulphate is used in making blue-black ink.

Stainless steel:

It is an alloy of iron, chromium, and nickel.
Used in making automobiles parts and utensils

Geography Short Notes - Our Solar System

2020-02-05T23:34:00.000+05:30

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Our Solar System

In this article, we have discussed "Important Facts of Solar System" which is asked in the Geography section of GK Section of Railways & SSC Exams. Direct GK questions are asked from Solar System topic. To help you study smarter and in an organized way, we are sharing important facts regarding the Solar System.

Important Facts of Solar System is
We live on a planet named ‘Earth’. Likewise, Earth also exists in its home with other 7 planets, only star ‘Sun’ and many other small objects called asteroids, comets, dwarf planets, meteors etc. So basically the Solar system is a system of Sun, 8 planets, dwarf planets, asteroids, meteors and comets under the gravitational influence of the Sun.

Origin

There are 3 to 4 major theories of the evolution of the universe and ultimately of the solar system. The prominent theory among all of these is the Big Bang theory.
According to this theory proposed by Georges Lemaitre, the universe is evolved from a small singularity and then expands over the next 13.8 billion years and still expanding.
It led to the formation of many billions of galaxies, solar systems, stars etc.
Our solar system lies in a spiral-shaped galaxy called ‘Milky Way’. The nearest galaxy to us is ‘Andromeda’.
Generally, there is a Black hole at the centre of every galaxy. ‘Sagittarius A’ is the black hole at the centre of Milky Way.
Solar System

In our solar system, 8 planets and many other celestial bodies revolve around the sun in elliptical orbits.
The dwarf planet named Pluto was removed from the list of the planets by the International Astronomical Union in 2006.
Sun is the powerhouse of the solar system. It is the only source of energy in the solar system.
Planet Mercury is nearest to the sun while Neptune is the farthest planet from the sun.
There is an asteroid belt between Mars and Jupiter. Planets inside the belt are distinctly different from those outsides in terms of size, mass, and composition etc.
Planets inside the belt are called Terrestrial planets and they are Mercury, Venus, Earth, and Mars. Planets outside the best are called Jovian planets and they are Jupiter, Saturn, Uranus, and Neptune.
Terrestrial planets are nearer to the sun, with metallic minerals and rock crust, with a thin atmosphere and have less number of natural satellites. While Jovian planets are away from Sun, made up of hot gases, have rings around them, and have a large number of natural satellites.

Facts about the Sun and Planets

1. Sun

The only star in our solar system and powerhouse of the solar system.
Composed of Hydrogen (73%), Helium (25%) gases and other metals. Sun carries almost 99% mass of our solar system.
Approximately 15 crore Kilometres further away from Earth. It takes around 8 minutes 30 seconds for light at the speed of 3 lakh Km/sec to reach the earth.
Temperature at surface= 5800 K or 5600 degree Celsius.
Temperature at the centre= 15.7 million K

2. Mercury

Closest planet to the Sun and very hot planet.
Smallest planet in the solar system with a diameter of 4900 Km.
Fastest Planet with speed of 172500 Km per hour to complete revolution around Sun in 88 days.
The planet with no water and gases like Nitrogen, Hydrogen, Oxygen and Carbon Dioxide.

3. Venus

Hottest planet in the solar system with the surface temperature of 478 degree Celsius.
Also known as “Earth’s Twin”. It is because of the similarity in size and mass between Venus and Earth.
One of the two planets in the solar system which rotate around the axis in a clockwise direction.
Brightest Star in the Solar system. It can be seen in the morning and evening with open eyes. So known as “Evening Star” and “Morning Star”.

4. Earth

The only Planet to give support to life with a pleasant atmosphere.
Also known as “Blue Planet” because of the presence of water on it.
It has one natural satellite named “Moon”.

5. Mars

Known as “Red Planet” because of Iron-rich red soil.
Second smallest planet in the solar system after Mercury.
Has two natural moons “Phobos” and “Deimos”.
Has a thin atmosphere and surface with valleys, craters, deserts, and ice caps etc.
“Olympus Mons” – Largest volcano and the tallest mountain in the solar system lies on Mars.

6. Jupiter

Largest planet of the solar system with the shortest rotation
Has an atmosphere filled with Hydrogen, Helium and other gases
The third brightest object in the night sky after the Moon and Venus.
Great Red Spot, a giant storm in the solar system exists on this planet.
Has at least 79 moons, including 4 large Galilean Moons “Io, Europa, Ganymede, and Callisto” which were discovered by Galileo. “Ganymede” is the largest among them.
It has an unclear ring around it.

7. Saturn

Second largest planet in the solar system and a gas giant.
Has bright and concentric rings around it which are made up of tiny rocks and pieces of Ice.
Saturn can float on water because it has less density than water.
Has at least 82 moons and Titan is the largest among them.

8. Uranus

Has the third-largest planetary radius and fourth-largest planetary mass in the Solar system.
Greenish in colour.
Discovered by William Herschel in 1781.
Known as “Ice Giant”. The atmosphere of Uranus is composed of Hydrogen and Helium primarily, but it also contains more water, ammonia etc.
Has coldest planetary atmosphere in the solar system.
Rotates clockwise on its axis like Venus but unlike other planets
Has at least 27 moons. Famous moons- Miranda, Ariel and Umbriel.

9. Neptune

Farthest planet from the Sun.
It is also “Ice Giant”. Atmosphere primarily composed of Hydrogen and Helium.
Bluish in colour because of Methane.
Fourth largest planet and the third most- massive planet in the solar system
Discovered by Johann Galle and Urbain Le Verrier in 1846. The only planet in the solar system found by Mathematical Predictions.
Has known 14 satellites. Famous moon – Triton.

10. Pluto

As per the new definition of Planets determined by International Astronomical Union (IAU), Pluto has been omitted from the list of planets in 2006.
Pluto is considered as a dwarf planet (size between planets and asteroids) now and it is a member of Kuiper Belt.
Kuiper Belt is a spherical boundary outside the orbit of Neptune containing a number of asteroids, rocks, and comets.

Other Space Objects.

1. Asteroids

These are small objects; rocks (mostly debris) revolve around the Sun.
They are mostly found in the Asteroid Belt which lies between the orbits of Mars and Jupiter.
These are also known as Minor planets.
Ceres, Vesta, Psyche are some famous and largest asteroids in the solar system.

2. Meteors and Meteorites

These are also known as Shooting stars.
Meteors are the small-sized rocky material which is generally formed due to asteroid collision and approaching the earth.
Because of Earth’s atmospheric layers, these small rocks burn before reaching the surface.
But there are some meteors which do not burn completely and land on Earth’s surface. They are called as Meteorites.
Willamette, Mbozi, Cape York, and El Chaco are some meteorites found on the Earth.
Lonar lake, Maharashtra in India is supposed to be created by a meteor impact in Pleistocene Epoch.

3. Comets

These are shiny, luminous “Tailed Stars”. These are rocky and metallic materials surrounded by frozen gases.
These are generally found in Kuiper Belt. They travel towards the Sun.
Their tail faces opposite of the sun and head faces towards the Sun.
They become visible when they travel close to the Sun.
Halley comet is famous which appeared last time in 1986 and which reappears after every 76 years.