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Some Important Programs for Java of Class 9

2020-11-23T11:34:00.012+05:30

Write a program for finding a sum of digits. for example - 123, sum of digits is 6

(Using do while loop)

/*Pay attention. This program will take user defined input from the user.*/

Input: Enter an integer 123

Output: Sum of digits = 6

Program Code -

import java.util.Scanner;

public class Digit_Sum_DoLoop

{

public static void main(String args[])

{

int m, n, sum = 0;

Scanner s = new Scanner(System.in);

System.out.print("Enter the number:");

m = s.nextInt();

{

n = m % 10;

sum = sum + n;

m = m / 10;

}while(m > 0);

System.out.println("Sum of Digits:"+sum);

}

Write a program for finding a product of digits. for example - 123, product of digits is 6

(Using do while loop)

/*Pay attention. This program will take user defined input from the user.*/

Input: Enter an integer 123

Output: Product of digits = 6

Program Code -

import java.util.Scanner;

public class Digit_Product_DoLoop

{

static int getProduct(int n)

{

int product = 1;

while (n != 0) {

product = product * (n % 10);

n = n / 10;

}

return product;

}

public static void main(String[] args)

{

Scanner s = new Scanner(System.in);

System.out.print("Enter the number:");

int n = s.nextInt();

System.out.println(getProduct(n));

}

Write a program to input an integer and check whether it is Palindrome or not, using do while loop.

A Palindrome number is a number whose reversed number is equal to the number. Eg 131,77,3443

(Using do while loop)

/*Pay attention. This program will take user defined input from the user.*/

Input: Enter an integer 131

Output: 131 is Palindrome number

Program Code -

import java.util.Scanner;

public class Palindrome_DoLoop

{

public static void main(String[] args)

{

int reversedInteger = 0, remainder, originalInteger;

Scanner s = new Scanner(System.in);

System.out.print("Enter the number:");

int num = s.nextInt();

originalInteger = num;

{

remainder = num % 10;

reversedInteger = reversedInteger * 10 + remainder;

num /= 10;

}while( num != 0 );

if (originalInteger == reversedInteger)

System.out.println(originalInteger + " is a palindrome.");

else

System.out.println(originalInteger + " is not a palindrome.");

}

Write a program to input an integer and check whether it is Spy or not?

A Spy number is a number whose sum of digits is equal to the product of digits.

Eg 1124

Sum of digits = 1+1+2+4 = 8

Product of digits = 1*1*2*4= 8

Input: Enter an integer 1124

Output: 1124 is a Spy number

import java.util.Scanner;

public class SpyNumber 
{
	public static void main(String[] args)
	{   
		int n,product=1,sum=0;
		int ld;

		Scanner sc = new Scanner(System.in);

		System.out.print("Enter the number :" );

		n=sc.nextInt();

		while(n>0)
		{
			ld=n%10;
			sum=sum+ld;
			product=product*ld;
			n=n/10;
		}

		if(sum==product)
			System.out.println("Given number is spy number");
		else
			System.out.println("Given number is not spy number");
	}
}

Write a program to input an integer and check whether it is Niven or not?

A Niven number is a number which is completely divisible by the sum of its digits. Eg 21, 18 Sum of digits of 21 = 3 21 is divisible by 3. Input: Enter an integer 21 Output: 21 is a Niven number

import java.util.*;
class Niven_Number
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
         
        System.out.print("Enter a number : ");
        int n = sc.nextInt();
        int c = n, d, sum = 0;
         
        do
        {
            d = c%10;
            sum = sum + d;
            c = c/10;
        }while(c>0);
         
        if(n%sum == 0)
            System.out.println(n+" is a Niven Number.");
        else
            System.out.println(n+" is not a Niven Number.");      
    }
}

`Write a program to input an integer and check whether it is Armstrongor not, using do while loop.`

public class Armstrong {

    public static void main(String[] args) {

        int number = 371, originalNumber, remainder, result = 0;

        originalNumber = number;

        do
        {
            remainder = originalNumber % 10;
            result += Math.pow(remainder, 3);
            originalNumber /= 10;
        }while (originalNumber != 0);


        if(result == number)
            System.out.println(number + " is an Armstrong number.");
        else
            System.out.println(number + " is not an Armstrong number.");
    }
}

`Write a program to input an integer and check whether it is Pronic ornot?`

import java.util.Scanner;

public class Example13Pronic {

    public static void main(String args[])
       {
        Scanner sc = new Scanner(System.in);
        System.out.print("Input a number : ");
        int num = sc.nextInt();
        int ans = 0;
    
        for(int i=0; i<num; i++)
        {
            if(i*(i+1) == num)
            {
                ans = 1;
                break;
            }
        }
         
        if(ans == 1)
            System.out.println("Pronic Number.");
        else
            System.out.println("Not a Pronic Number.");      
    }
}

`Write a program to input an integer and check whether it is Disarium ornot?`

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53 import java.util.Scanner;
 
public class JavaDisariumNumberProgram 
{
    private static boolean isItDisariumNumber(int inputNumber)
    {
        int noOfDigits = Integer.toString(inputNumber).length();
         
        int copyOfInputNumber = inputNumber;
         
        int sum = 0;
         
        while (inputNumber > 0)
        {
            int lastDigit = inputNumber % 10;
             
            sum = sum + (int) Math.pow(lastDigit, noOfDigits);
             
            inputNumber = inputNumber / 10;
             
            noOfDigits--;
        }
         
        if (sum == copyOfInputNumber)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
     
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
         
        System.out.println("Enter a number :");
         
        int inputNumber = sc.nextInt();
         
        if (isItDisariumNumber(inputNumber))
        {
            System.out.println(inputNumber+" is a Disarium number");
        }
        else
        {
            System.out.println(inputNumber+" is not a Disarium number");
        }
         
        sc.close();
    }
}

Write	a	program	to	input	time	in	seconds	and	
display	the	time	broken	up	as	hours,	minutes	and	
seconds.
import java.util.*;
public class Exercise55 {
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
System.out.print("Input seconds: ");
int seconds = in.nextInt();
int p1 = seconds % 60;
int p2 = seconds / 60;
int p3 = p2 % 60;
p2 = p2 / 60;
System.out.print( p2 + ":" + p3 + ":" + p1);
System.out.print("\n");
}
}

Write	a	program	to	input	a	floating	point	number	
and	round	it	off	to	the	nearest	integer.

class Main_concne
{
    public static void main(String[] args)
    {
        float x = 5.60f;
        int y = (int)x;
        System.out.println("y = " + y);
    }
}


Write	a	program	to	input	the	Basic	Pay	of	an	
employee	and	find	the	gross	pay	of	the	employee	
for	the	following	allowances	and	deductions 

public class employee
{
public static void main(double salary)
{
double allowance=30/100*salary;
double rent =15/100*salary;
double pf=12.5/100*salary;
double gross=salary+allowance+rent;
double net=salary-pf
System.out.println("gross pay=Rs."+gross);
System.out.println("net pay=Rs."+net)'
}
}

Write	a	program	 to	accept	3	sides	of a	triangle,
And	check	whether	it	can	form		a	triangle	or	not.If	
it	forms	a	triangle	,	check	whether	it	is an	acute	
angled,	obtuse	angled	or right	angled	triangle.

public class accept3s
{
public static void main(String[] args)
{
Scanner Sc=new Scanner (System.in);
int a,b,c;
a=Sc.nextInt();
b=Sc.nextInt();
c=Sc.nextInt();
if((a+b+c)==180)
{
System.out.println("Triangle possible");
if (a==90)
System.out.println("Right angled");
else if ((a<90)&&(a>0))
System.out.println("Acute angle");
else if (a>90)&&(a<180)
System.out.println("Obtuse angled");
}
else
System.out.println("not possible");
}
}

A	library	charges	a	fine	for	books	returned	late.	
Following	are	the	fines

class retLate
{
public static void main(String args[])
{
double fine=0.0; int n;
System.out.println("Enter the no of days late");
n = 5
if(n<=5)
fine=0.40*n;
else if(n<=10)
fine=0.65*n;
else
fine=0.80*n;
System.out.println("Fine = "+fine);
}
}

Write	a	menu	driven	program	to	input	an	integer	
and	a	choice	of	character	by	the	user	as	M	or	B.	If	
choice	is	M	check	whether	the	number	is	Magic	or	
not.


class MagicNum 
{ 
   public static boolean isMagic(int n) 
   { 
       int sum = 0; 
       

       while (n > 0 || sum > 9) 
       { 
           if (n == 0) 
           { 
               n = sum; 
               sum = 0; 
           } 
           sum += n % 10; 
           n /= 10; 
       } 
       
       return (sum == 1); 
   } 
    
   public static void main(String args[]) 
    { 
     int n = 1234; 
     if (isMagic(n)) 
        System.out.println("Magic Number"); 
           
     else
        System.out.println("Not a magic Number"); 
    } 
}

Write	a	program	to	input	three	integers	and	check	
whether	it	forms	Pythagorean	triplet	or	not.

import java.io.*; 
import java.util.*; 
  
class PythaTriCon { 
  
    static void pythagoreanTriplets(int limit) 
    { 
  
        int a, b, c = 0; 
  
        int m = 2; 
  
   
        while (c < limit) { 
  
            for (int n = 1; n < m; ++n) { 
  
                a = m * m - n * n; 
                b = 2 * m * n; 
                c = m * m + n * n; 
  
                if (c > limit) 
                    break; 
  
                System.out.println(a + " " + b + " " + c); 
            } 
            m++; 
        } 
    } 
  
    public static void main(String args[]) 
    { 
        int limit = 20; 
        pythagoreanTriplets(limit); 
    } 
}

1 and 2 are the zeros of the polynomial p(x) = (x - 1) (x - 2)

2020-11-02T22:30:00.008+05:30

Verify that :- 1 and 2 are the zeros of the polynomial p(x) = (x - 1) (x - 2)

1 and 2 are zeros of polynomial means that if the value is substituted for x then the equation turns zero.

So let's prove using x = 1, first

\[p(x)=(x-1)(x-2)\]\[p(x)=(1-1)(1-2)\]\[p(x)=(0)(-1)\]\[p(x)=(0)\]

Since the equation turns to be zero, 1 is the zero of the polynomial.

Now let's take x = 2

Since the equation turns to be zero, 2 is also the zero of the polynomial.

Hence Verified !!

Hope it helps !!

Cheers !!

find two rational numbers between root 2 and root 3

2020-11-01T20:55:00.059+05:30

Solution -

sabse pehle \[\sqrt{2}\] ki numerical value (up to 50 decimal places) yeh hoti hai \[\sqrt{2}\] \[=1.41421356237309504880168872420969807856967187537694…\] numerical value 10 triliyan numbers ki calculation hai. For general use, isske value ko kaat diya jaata hai aur calculation ko aasaan banaane ke lie 1.414 ke roop mein upyog kiya jaata hai. \[=1.414...\] Yeh value pehle se hi non-terminating value hogi.

issi tarah se \[\downarrow\]

\[\sqrt{3}=1.732\]

now, ab dono numbers ke 3 decimal places tak ke number, ko lelenge. \[\sqrt{2}=1.414 ,\color{white}{s} \sqrt{3}=1.732\] ab dono numbers ke beech se 1 decimal place ki value lelenge.

jese 1.4 se 1.7 ke beech me 1.5 ho skta hai

jese 1.4 se 1.7 ke beech me 1.6 hai

par kya 1.4 se 1.7 ke beech me 1.7 ho skta hai?
nahi !! kyunki wo condition ke equal hai.

Two rational numbers lying between \[\sqrt{2} \color{white}{s}and\color{white}{s} \sqrt{3}\color{white}{s} is \color{white}{s}1.5,\color{white}{s}1.6\].

Multiplication Table

2020-10-10T08:22:00.006+05:30

Learn Multiplication Table of 1 to 25

Free of Cost Courses are LImited Time Availability by Newtronlearner [Click here see all info]

2020-09-10T10:48:00.007+05:30

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Carbon and Its Compounds

2020-02-14T16:39:00.000+05:30

Some topics covered in the chapter include:

Carbon- symbol C; atomic number 6; non-metallic.

Oxides of carbon are formed when carbon is combined with oxygen. The two main oxides of carbon thus formed are:

Carbon monoxide
Carbon dioxide

The tetravalency and the property of catenation that is exhibited by carbon make it a versatile element.

Allotropy- It is the phenomenon by which two or more different physical forms of a chemical element exist. The multiple physical forms are known as allotropes. The two allotropes of carbon are diamond and graphite.
Petroleum- complex mixture of solid, liquid and gaseous hydrocarbons with earthy particles and salt water.

Question 1.

Fill in the blanks.

(a) Carbon is present in both living and non-living things.

(b) The tendency of an element to exist in two or more forms but in the same physical state is called Allotropy.

(d) Diamond is the hardest substance that occurs naturally.

(e) The name ‘carbon’ is derived from the Latin word carbo.

Question 2.

Choose the correct alternative.

(a) In combined state, carbon occurs as

(i) coal

(ii) diamond

(iii) graphite

(iv) petroleum

Answer: (iv) petroleum

(b) A crystalline form of carbon is

(i) lamp black

(ii) gas carbon

(iii) sugar

(iv) fullerene

Answer: (iii) sugar

(i) Bihar

(ii) Maharashtra

(iii) Orissa

(iv) Rajasthan

Answer: (ii) Maharashtra

(d) Diamond is used for

(i) making the electrodes of electric furnaces.

(ii) making crucible for melting metals.

(iii) cutting and drilling rocks and glass.

(iv) making carbon brushes for electric motors.

Answer: (iii) cutting and drilling rocks and glass.

(e) Carbon forms innumerable compounds because

(i) it has four electrons in its outermost shell.

(ii) it behaves as metal as well as a non-metal.

(iii) carbon atoms can form long chains.

(iv) it combines with other elements to form covalent compounds.

Answer: (iii) carbon atoms can form long chains.

Question 3.

Write ‘true’ or ‘false’ against the following statements.

(a) Carbon constitutes 0.03% of the earth’s crust.

Solution: True

(b) Graphite is the purest form of carbon.

Solution: False

(d) Graphite has layers of hexagonal carbon bondings.

Solution: True

(e) Diamond is insoluble in all solvents.

Solution: True.

Question 4.

Define the following terms:

(a) Allotropy

(b) Carat

(d) Catenation

Solution:

(a) Allotropy: The phenomenon due to which an element exists in two or more forms in the same physical state with identical properties but with different physical properties is known as allotropy.

(b) Carat: The weight of diamond is expressed in carats [1 carat = 0.2 g]

(c) Crystal: A homogeneous solid in which particles such as atoms, molecules or ions are arranged in definite pattern due to which they have definite geometrical shape with plane surfaces is called a crystal. eg. sugar and sodium chloride.

(d) Catenation: There is a unique property of carbon called catenation through which a large number of organic compounds is due to the ability of carbon atom to form long chains with other carbon atoms through the sharing of electrons.

Question 5.

State the terms:

(a) Substances whose atoms or molecules are arranged in a definite pattern.

Solution: Crystals.

(b) Different forms of an element found in the same physical state.

Solution: Allotropy.

Solution: Catenation

Question 6.

Name the following:

(a) The hardest naturally occurring substance.

Solution: Diamond.

(b) A greyish black non-metal that is a good conductor of electricity.

Solution: Graphite.

Solution: Fullerenes.

Question 7.

Answer the following questions:

(a) Why is graphite a good conductor of electricity but not a diamond?

Solution:

One valence electron of each carbon atom remains free in a graphite molecule, thus making graphite a good conductor of electricity. Whereas in diamond, they have no free mobile electron. That is why diamond is a bad conductor of electricity.

(b) Why is diamond very hard?

Solution:

A diamond is a giant molecule. There are 4 valence electrons in carbon atom where each carbon atom is linked with four neighbouring carbon atoms. Thus forming a rigid tetrahedral structure. It is the strong bonding that makes diamond the hardest substance.

Solution:

Fullerenes: Fullerenes are the third crystalline form of carbon. They have been found to exist in interstellar dust as well though they were discovered only recently as in the geological formations of the earth. Common fullerenes are C-32, C-50, C-70 and C-76

(d) What impurity is present in black diamond?

Solution:

Copper oxide present in black diamond is impurity.

(e) Explain the softness of graphite with reference to its structure.

Solution:

Each carbon atoms is linked with three neighboring carbon atoms in a graphite molecule. Thus forming a hexagonal arrangement of atoms. These hexagonal grouping of carbon atoms are arranged as layers or sheets piled on the top of other. The layers are held together by weak forces such that they can slide over one another. That is why graphite is soft.

Question 8.

Give two uses of

(a) graphite

(b) diamond.

Solution:

(a) Two uses of graphite:

1. For making the electrodes of electric furnaces.

2. For making crucibles for melting metals due to its high melting points.

(b) Two uses of diamond:

1. Diamond is used in jewellery as a gem

2. It is used for cutting and drilling rocks, glass,

Question 9.

Write three differences between graphite and diamond.

Solution:

Differences between diamond and graphite.

Diamond	Graphite
1. Pure diamond is colourless and transparent.	1. Graphite is greyish black opaque and shiny.
2. It is the hardest naturally occurring substance.	2. It is soft and greasy to touch.
3. It has high density i.e. 3.5 g/cm3	3. It has low density i.e. 2.39g/cm3.
4. It is a bad conductor of electricity.	4. It is a good conductor of electricity.
5. It burns in air at 900°C to form carbon dioxide.	5. It burns in air at 700°C to form carbon dioxide.

Exercise – II

Question 1.

Fill in the blanks:

(a) Charcoal is formed when charcoal is burnt in a limited supply of air.

(b) Coal is a amorphous form of carbon.

(d) Wood charcoal is a bad conductor of heat and electricity.

(e) Lampblack is used in making black shoe polish.

Chemical reaction part 2

2020-02-01T16:12:00.003+05:30

What are thermal decomposition reactions? Explain with an example.

Answer:

Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically Decomposes. The Reaction is usually endothermic as heat is required to break chemical bonds in the compound undergoing decomposition.

What information is conveyed by a balanced chemical equation?

A chemical equation defines most of the major facts about any reaction.

The basic knowledge that is conveyed by a balanced chemical equation are as follows:

1. The respective formulas of the reactants and products.

2. The respective masses of the reactants and products.

3. The total number of molecules involved in the process.

Give 2 examples of each of the following changes occurring during a chemical reaction :

1) Change of state of the reactants

2) Change of colour

3) Evolution of gas

4) Formation of precipitate

Answer:

Characteristics of chemical reaction:

1) Change of state of the reactants:

Example:

Ammonia gas reacts with hydrogen chloride gas to produce solid ammonium chloride.

2)Change of colour

Example:

Wehne few pices of Fe are added to the blue copper sulphate solution, the colour of the solution fades

and turns into light green due to the formation of ferrous sulphate.

3)Evolution of gas

Example:

4) Formation of precipitate

Example:

When silver nitrate is added to sodium chloride, white insoluble precipitate of silver chloride is formed.

When ferrous sulphate solution is added to the sodium hydroxide, a dirty green precipitate ferrous hydroxide is formed.

With the help of experiment, show the effect of heat on lime stone.

Answer:

Let's stick to limestone, calcium carbonate. When heated it will decompose to form carbon dioxide and calcium oxide. ... When water is added to calcium oxide the results is an exothermic reaction (heat given off) as the water hydrates the oxide to form a hydroxide by a process of slaking. Hence slaked lime.

Chemical reaction part 1

2020-02-01T16:07:00.000+05:30

Difference between in Positive catalyst, Negative catalyst and Promoter

i.  Positive catalyst

     It is a catalyst which speeds up the rate of the reaction.

Examples: MnO2, V2O5, Pt

  ii.  Negative catalyst

      It is a catalyst which reduces the rate of reaction.

  Example: Alcohol

  iii. Promoter

  It is added to a catalyst to increase its efficiency.

      Example: Molybdenum

Difference between in Exothermic and Endothermic reaction

An exothermic process releases heat, causing the temperature of the immediate surroundings to rise.

An endothermic process absorbs heat and cools the surroundings.”

What are oxides and its types with examples

Oxides are a chemical compound with one or more oxygen atoms combined with other elements

Types of oxides

1) Acidic oxide: oxides are oxides of nonmetals.

example :

SO_2, CO_2 , SO_3

2) Basic oxides: These are oxides of metals

CaO, MgO, Na_2O

3) Amphoteric oxides: Which shows both basic as well as acidic properties.

example :

ZnO , Al_2O_3

4) Neutral oxides: Shows neither acidic nor basic properties

example;

N_2O, NO, CO

What is redox reaction? Give an example,why is the melting point of ice formed from tap water is below 0°c ?

Answer:

Redox reactions are chemical reactions involving simultaneous reduction of one substance (gain of electrons) and oxidation of another substance (loss of electrons).

These reactions are always coupled.

One reactant undergoes oxidation and another is reduced.

An example :

Cl2 + 2KI -------> 2KCl + I2

Here Cl2 is reduced and KI is oxidized.

Tap water contains many impurities and minerals.

Presence of impurities in water makes it a simple solution. Such solutions undergo depression in freezing point/melting point.

As a result of this depression, tap water melts below 0°C.

What do you understand by redox reaction

Answer:

Those reactions in which both oxidation and reduction takes place is called redox reaction

Define chemical reaction

Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products.

What are displacement reactions. give suitable examples

Important Terms of Chemistry

2020-02-01T15:38:00.002+05:30

Activation energy (in chemistry) The minimum energy needed for a particular chemical reaction to take place.

Atom The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and neutrally charged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

Bond (in chemistry) A semi-permanent attachment between atoms — or groups of atoms — in a molecule. It’s formed by an attractive force between the participating atoms. Once bonded, the atoms will work as a unit. To separate the component atoms, energy must be supplied to the molecule as heat or some other type of radiation.

Carbon The chemical element having the atomic number 6. It is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules.

Catalyst A substance that helps a chemical reaction to proceed faster. Examples include enzymes and elements such as platinum and iridium.

Catalytic converter A device made of honeycomb-shaped ceramic structures that is put onto the tailpipe of a vehicle. As exhaust gases flow through it, they encounter two different types of catalysts, each able to foster a different type of chemical reaction. One or more metals, usually platinum, rhodium, palladium — and sometimes even gold — coat the inside of the system. All of the walls of the device’s honeycomb structure increase greatly the area of catalyst-covered surfaces now available to react with the exhaust. As the gases from the engine hit these metal coated surfaces, they break apart the pollutants, turning them into less harmful materials. A sensor in the converter also measures how much oxygen is in the exhaust. If it finds too much, it tells a computer to adjust the air-to-fuel ratio in the engine so that it will burn more cleanly.

Chemical A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.

Chemical bonds Attractive forces between atoms that are strong enough to make the linked elements function as a single unit. Some of the attractive forces are weak, some are very strong. All bonds appear to link atoms through a sharing of — or an attempt to share — electrons.

Chemical reaction A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas).

Clectricity A flow of charge, usually from the movement of negatively charged particles, called electrons.

Engine A machine designed to convert energy into useful mechanical motion. Sometimes an engine is called a motor.

Enzymes Molecules made by living things to speed up chemical reactions.

Exhaust (in engineering) The gases and fine particles emitted — often at high speed and/or pressure — by combustion (burning) or by the heating of air. Exhaust gases are usually a form of waste.

Fuel cell A device that converts chemical energy into electrical energy. The most common fuel is hydrogen, which emits only water vapor as a byproduct.

Genetic Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.

Hydrogen The lightest element in the universe. As a gas, it is colorless, odorless and highly flammable. It’s an integral part of many fuels, fats and chemicals that make up living tissues.

Iridium Discovered in 1803, its name comes from the Latin for rainbow. It’s a hard, brittle and corrosion-resistant metal in the platinum family. Slightly yellowish, the principle use for this element is as a hardener for platinum. Indeed, its melting point is more than 2,400° Celsius (4,350° Fahrenheit). The element’s atomic number is 77.

Manufacturing The making of things, usually on a large scale.

Metal Something that conducts electricity well, tends to be shiny (reflective) and malleable (meaning it can be reshaped with heat and not too much force or pressure).

Molecule An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

Nutrient A vitamin, mineral, fat, carbohydrate or protein that a plant, animal or other organism requires as part of its food in order to survive.

Oxygen A gas that makes up about 21 percent of the atmosphere. All animals and many microorganisms need oxygen to fuel their metabolism.

Palladium A soft, ductile, steel-white, tarnish-resistant, metallic element occurring naturally with platinum, especially in gold, nickel, and copper ores.

Petroleum A thick flammable liquid mixture of hydrocarbons. Petroleum is a fossil fuel mainly found beneath the Earth’s surface. It is the source of the chemicals used to make gasoline, lubricating oils, plastics and many other products.

Plastic Any of a series of materials that are easily deformable; or synthetic materials that have been made from polymers (long strings of some building-block molecule) that tend to be lightweight, inexpensive and resistant to degradation.

Platinum A naturally occurring silver-white metallic element that remains stable (does not corrode) in air. It is used in jewelry, electronics, chemical processing and some dental crowns.

Pollutant A substance that taints something — such as the air, water, our bodies or products. Some pollutants are chemicals, such as pesticides. Others may be radiation, including excess heat or light. Even weeds and other invasive species can be considered a type of biological pollution.

Chapter 18

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Exercise 18-A

Exercise 18-B

Solution 4
We have been given that 1 mile= 1.6 kilometres
We also know that 1 km=1000 meters so
by multiplying on both sides
1.6×1000=1×1000
1600m is to 1000m
This means that miles and kilometres are in ratio of
1.6:1 so...
(a)4.5×1.6
=9.20km
This means that 4.5 miles is equal to 9.20km

(B)we have been given that 1 mile = 1km so...
let's take the H as no. of miles so...
H×1.6=8
taking left hand side and right hand side.
H=8÷1.6
H = 5
approximately 5 miles will be equal to 8 km

Solution 5

Exercise 18-C

Solution 2

Scale on x-axis, 1 cm = 10 minutes. Scale on y-axis, 1 cm = 100 metres.
The aeroplane rose upto 10 minutes of 1000 metres
100 metres per minutes
40 + 40 = 80 minutes
130 minutes

Chapter 15

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Solution 12
It is given that ABCD is a kite in which ∠CAD=70°, ∠CBD=65° and ∠A=∠C.

Now, in ΔACD, we have

∠A+∠C+∠D=180° (Angle sum property)

⇒∠CAD+∠ADC+∠ACD=180°

⇒70°+70°+∠ADC=180°

⇒∠ADC=40°

Now, From ABCD, we have

∠A+∠B+∠C+∠D=360° (Sum of all the angles of quadrilateral is 360°)

⇒∠BAD+∠ABC+∠BCD+∠CDA=360°

⇒2(∠CAD)+2(∠CBD)+∠BCD+∠CDA=360°

⇒2(70)+2(65)+∠BCD+40=360°

⇒∠BCD=50°

Solution 13

Electricity

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Its form of energy which exists due to charges. its a controllable and convenient form of energy used in different forms like light, heat and mechanical energy.

Electricity due to static this known Static Energy.

Electricity due to motion of charges is known as Current Electricity.

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It Means Static बिजली किसी material (सामग्री) की सतह पर या उसके भीतर current (विद्युत) आवेशों का असंतुलन है। चार्ज तब तक रहता है जब तक वह current (विद्युत) प्रवाह या current विद्युत discharge (निर्वहन) के माध्यम से दूर जाने में सक्षम नहीं होता है।

Examples of static energy

Rubbing a balloon on your hair
Walking across carpet
Clothes tumbling in dryer
Lightning
Getting "shocked" by someone
Hair standing up after jumping on a trampoline
Laundry sticking together
Combing or brushing clean by hair

Treasure Hunt Quiz

Static Electricity

Surprise Test

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Q: If the difference between the compound interest and simple interest on a certain sum of money for 2 years at 25/2 per annum is 150 rs.the sum is:

Solution

r=12.5%

Diff=[P(1+12.5/100)^n-P] - [P*12.5/100*n

- P ] = 150

[P(1+0.125)^2-P]-[P*0.125*2-P]

=150

[1.125^2*P-P]-[0.25P-P]=150

P[1.265625-1]-[-0.75P]=150

P*(0.265625+0.75)=150

P=150/1.015625

=147.69

Q: If the amount is 9/4 times the sum after 2 years at compound interest. find the rate

Solution

Here is your answer

Let Sum be X then A =9X/4.
T = 2 years. R = ?
ATQ
9X/4= X(1+R/100)2
(3/2)2= (1+R/100)*2
3/2 = 1+ R/100
R/100 =3/2 - 1
R =1/2(100)
R = 50%

Q: The time in which Rs 1800 amounts to Rs 2178 at 10% per annum,compounded annually is ?

Solution

2178 = 1800(1+10/100)^n (The formula is P(1+r/100)^n)
2178/1800 = (1+10/100)^n
121/100 = (11/10)^n
(11/10)^2 = (11/10)^n
n = 2.

Q: The compound interest on a certain sum at 5% p.a. for 2 year is 328. The simple interest on that sum at the same rate and for the same period will be

Solution

Heat Transfer

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Important Questions

Question 1: Compare and contrast boiling and evaporation.

• Evaporation:-

1) Evaporation is the process of conversion of a liquid into vapours at any temperature below its boiling point.

2) In the process of evaporation, bubbles are not formed.

3) It is slower than the process of boiling (Slow process).

4) It occurs at all/any temperature.

5) In the process of evaporation, temperature may change.

6) Energy supplied by the surroundings.

• Boiling:-

1) Boiling is the process by which a liquid turns into a vapor when it is heated to its boiling point.

2) In the process of boiling, bubbles are formed.

3) It is faster than the process of evaporation (Quick process).

4) It occurs at a definite/fixed temperature (boiling point).

5) In the process of boiling, temperature remains constant.

6) Energy supplied by a source of energy.

Difference of Boiling and Evaporation

Question 2: Describe thermal expansion of matter.

Thermal expansion is the tendency of a matter to change in shape, area and volume in response to the change in temperature, through heat transfer.

Solid has greater intermolecular forces than liquid and gas so thermal expansion order of three states of matter is:- gases > liquid > solid

Question 3: Describe linear, area and volume expansion.

Thermal expansion. It is usually expressed as a fractional change in length or volume per unit temperature change; a linear expansion coefficient is usually employed in describing the expansion of a solid, while a volume expansion coefficient is more useful for a liquid or a gas.

Question 4: Compare expansivity in Solids, Liquids and Gases.

Heating makes the particles expand or become loose.

Cooling makes the particles contract or tight.

Gas expand the most

Solid can't be expand it have definite shape.

Liquid can be partially expand .

Gas can be highly expand .

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Very Important Questions

Difference between boiling and evaporation ?
Thermal Expansion ?
Linear Expansion ?
Volume Expansion ?
Superficial Expansion ?
Compare Expansion in Solids, Liquids and Gases ?
Examples and Real world applications of Expansion ?

Exercise 13 (B)

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Solve 1
Let x n y be the number
X be greater than Y.
ATP:
X=12+y.......1
X+y=10.......2
Substitute 1 in 2
(12+y)+y=10
12+2y=10
2y=-2
Y=-1
X=12+(-1)
=11

Solve 2
Let the smaller number be x
let the larger number be y
then according to question
y= 5x............(1)
y-18=3x
5x-18= 3x (from(1) )
5x-3x= 18
2x = 18
x= 9
y= 5x
y= 9*5=45

Solve 3
[1]
36, 35, 37
x-1 + x + x+1 = 108
3x = 108

x = 36

[2]

Given,

sum of three consecutive odd numbers is 93.

Let,1st no.=x

2nd no.=x+2

3rd no.=x+4

According to problem,

x+x+2+x+4=93

==3x+6=93

==3x=93-6

==3x=87

==x=87/3

==x=28

therefore,

1st no.is 29

2nd no.is 31

3rd no.is 33

[3]

Required three consecutive even numbers are 80,82 and 84
Step-by-step explanation:
Let x ,(x+2) and (x+4) are three consecutive even numbers.
According to the problem given,
Sum of these numbers = 246
=> x+x+2+x+4 = 246
=> 3x + 6 = 246
=> 3x = 246 - 6
=> 3x = 240
/* Divide each term by 3, we get
=> x = 80
Therefore,
Required three consecutive even numbers are
x = 80,
x + 2 = 80 + 2 = 82 ,
x + 4 = 80 + 4 = 84

[4]
Let the first consecutive multiples of 7 be 7x.
Then,
second consecutive multiples of 7 = 7(x+1)
third consecutive multiples of 7 = 7(x+2)
According to question,
7x + 7(x+1) + 7(x+2) = 777
=> 7x + 7x + 7 + 7x + 14 = 777
=> 21x + 21 = 777
=> 21x = 777 - 21
=> 21x = 756
=> x = 756/21
=> x = 36
Hence, the first consecutive multiples of 7
= 7 × 36 = 252
Second consecutive multiples of 7 = 7 × 37 = 259
Third consecutive multiples of 7 = 7 × 38 = 266.

Solve 4
Let the first part be x
Then second part = 2x-32
Third part = x+18
Their sum = 534
x+2x-32+x+18 = 534
4x-14 = 534
4x = 534+14
4x = 548
x = 548/4
x = 137

First part = 137
Second part = 2(137)-32
= 274-32 = 242
Third part = 137+18 = 155

Solve 5
Numbers are n, n+2 and n+4
3n-7 = 2(n+4)
3n-7 = 2n+8
3n-2n = 8+7 n = 15
Answer: 15, 17 and 19

Solve 6
Let one number be x
other no =x+7
(x+7)² -77 =x²
x²+49+14x-77=x²
x²-28+14x=x²
x²-x²+14x = 28
14x= 28
x= 2
other no = x+7 =2+7 =9
the numbers are 2 and 9

Solve 7

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Solve 8
Let the numerator be x
Then, the denominator will be x+3
ATQ
x+5/x+3+5=4/5
x+5/x+8=4/5
5 (x+5)=4 (x+8)
5x+25=4x+32
5x-4x=32-25
x=7
The fraction is 7/10

Solve 9
Required two integers are ,
Required two integers are ,first integer = 25,
Second integer = 75

Step-by-step explanation:
Given ratio of two integers = 1:3
Let first integer = x,
Second integer = 3x
According to the problem given,
"The difference between two positive integers is 50 "
3x-x = 50
=> 2x = 50
=> x = 50/2
=> x = 25
Therefore,
Required two integers are ,
first integer =x = 25,
Second integer = 3x = 3×25 = 75

Solve 10

The two digit number is

25

Explanation:

Let tens digit and units digit of the number be

x and y; x + y = 7; (1)

The two digit number is

10 x + y

, when reversed,

the two digit number becomes

10 y + x

, by given condition,

10 y + x = 10 x + y + 27 or 9 y - 9 x = 27

9 (y - x) = 27 or (y - x) = 3 or y = x + 3

Putting

y = x + 3

in equation (1) we get,

x + x + 3 = 7;

2 x = 4 ∴ x = 2; y = 2 + 3 = 5

Hence the two digit number is

25

[Ans]

Solve 11
Let the age of Vijay be x years.
Then the age of Sushma is 15 years older than Vijay = (x+15) years.
Given that in 3 years she will be 8 times as old as Vijay was 3 years ago.
(x + 15) + 3 = 8(x - 3)
x + 15 + 3 = 8x - 24
x + 18 = 8x - 24
7x = 42
x = 42/7
x = 6.
If Vijay's present age is 6 years, Then the age of Sushma = (x+15) = 21 years.
The age of Vijay = 6 years.
The age of Sushma = 21 years.

Solve 12
Let sanjay bro's present age= x
Sanjaya's age= x/2
after 6 years, sanjaya bro's age will be = x+6, Sanjay will be = x/2+6
as per question
x/2+6=3/5(x+6)
=>x/2+6=3x/5+18/5
=>6-3.6=3x/5-x/2
=>2.4=x/10
=>x=24
Sanjay's bro is 24 yrs old and sanjay is 12 yrs old.

Solve 13
Area of rectangle = l*b
=8(x-5)
=8x-40
given area is 3x cm sq
so 8x-40=3x
8x-3x=40
5x=40
so x=8
if perimeter is 40
perimeter =2(l+b)
=2(8+(x-5))
=2(8+x-5)
=2(3+x)
=6+2x
6+2x=40
2x=34
x=17

Solve 14
Length = 25 m
breadth = b (say)
area = 225
25 x b = 225
b = 9
now
perimeter = 2( 25 + 9) = 2x34 = 68 m
so
4(x-2) = 68
x - 2 = 68/4
x - 2 = 17
x = 19

Solve 16

In right triangle ABC, angle A= 90°
AB:AC=3:4
Therefore, AB=3x and AC=4x
By pythagoras theorem

BC=√AC×AC+AB×AB
BC=5x
Now, In rectangle BCDE , Length =BC=5x
Since, BC= 4/5×5x=4x
But,
Perimeter = 180cm
2×(5x+4x)=180
x=10
since, the shortest side of right ∆ ABC=3x
= 3×10
=30cm.

Solve 17

Average Speed of Car A=x km/hr

Average speed of Car B=x+5 km/hr

Average Speed of Two Cars A+B=425/5=85km/hr

x+(x+5)=85

2x+5=85

x=40 km/hr

A=40 km/hr & B=45 km/hr

Solve 18
Let the speed of first car be x km/hr
speed of 2nd car =x*8/9 =8x/9 km/hr

after 7 hrs distance travelled
by 1st car=7*x=7x km
by 2nd car=7*8x/9=56x/9
now
A/q
7x+56x/9 =595
63x+56x=595*9
=119x=595*9
x=595/119 *9
=x=45
speed of first car =45 km/hr
speed of second car=45*8/9 =40 km/hr

Solve 19
Let the speed of the boat in still water be x.
Given that the speed of the stream is 2 km/h.
Upstream:
Speed = ( x - 2) km/h
Distance = Speed x Time
Distance = 6 (x - 2) km
Downstream:
Speed = ( x + 2) km/h
Distance = Speed x Time
Distance = 5(x + 2) km
Solve x:
Since both the distance are the same:
6(x- 2) = 5( x + 2)
6x - 12 = 5x + 10
x = 22 km/h
Answer: The speed of the boat in still water is 22 km/h

Solve 20
Step-by-step explanation:
Let s = speed of the boat in still water
then
(s-4) = speed upstream
and
(s+4) = speed downstream
Distance both ways is equal. Make a distance equation; Distance = Time * speed
Up distance = down distance
25(s-4)= 20(s+4)
25s - 100 = 20s + 80
25s - 20s = +100 + 80
5s = 180
s = 180/5
s = 36 mph
Find the distance:
Dist = time * speed
downstream: d = 20(36+4) = 800 mi
and
Upstream: d = 25(36-4) = 800 mi also

Solve 21
She bought:10 rupee cards: x
5 rupee cards: 2/3 x
15 rupee cards:1/5 x
So the equation is 10x + 5*(2/3 x) + 15(1/5 x) = 245
So
x = 15
So
She bought:10 rupee cards: 15
5 rupee cards: 10
15 rupee cards:3

Solve 22
enrolment this year = 552
let the last year's enrolment be x
so this year's enrolment is 115x/100
ATQ,
23x/20=552
⇒x=552X20/23=480
so last year's enrolment was 480 students.

Solve 23
let the no of orange bought by the vendor be X
according to question:
no of orange bought by the vendor = no of banana bought by the vendor = X
now;
cost of orange at which vendor bought =5rs
then cost of X no of orange will be = 5X rs
cost of banana at which the vendor bought = 2 rs
then cost of X no of banana will be = 2X rs
also, according to the question:
vendor sells the orange at a profit of 20% i.e, he sells it at the price of =
5X ×20/100 +5X= 6X rs
also vendor sells the banana at a profit of 15% i.e,he sells it at the price of=
2X×15/100 +2X= 23X/10 rs
according to the question his total profit is 390 rs i.e,
(final price of orange- initial price of orange) +(final price of banana - initial price of banana) =390 rs
(6X-5X) + (23X/10-2X) = 390
X +3X/10 =390
13X/10 = 390
X =390 ×10/13
X=300

Solve 27
Answer - The the total money spent by them is Rs 117
Given that:
Nine persons went to a hotel for taking their meals
Eight of them spent rupees 12 each over there meals
Total amount spent by 8 of them is:
= 12 x 8 = 96
So total amount spent by 8 of them is Rs 96
Let "x" be the amount spent by all of them
The ninth spend rupees 8 more than the average expenditure of all the nine
amount spent by ninth person = 8 + x/9
According to given question,

amount spent by all of them = total amount spent by 8 of them + amount spent by ninth person
x = 96+8+x/9
x = 864+72+x/9
9x - x = 936
x = 936/8
Thus the the total money spent by them is Rs 117

Chemical Reactions

2020-01-20T16:57:00.000+05:30

The more common types of chemical reactions are as follows:

Combination.

Decomposition.
Single displacement.
Double displacement.
Combustion.
Redox.

The Activity Series of Some Common Metals
Activity	Metal
Most active	Alkali and alkaline earth metals

Al

Zn

Cr

Fe

Ni

Sn

Pb

Cu

Ag
Least Active	Au

Exercise 10

2020-01-20T16:34:00.000+05:30

Solve 1
Number of days required by 6 men to complete the work = 7
Number of days required by 1 man to complete the work = 7 × 6
Number of days required by 21 men to complete the work = 42/21 = 2
Hence, 2 days is required by 21 men to complete the work

Solve 2
Shashi weaves one basket in 35/25 =7/5 days
shashi weaves 110 baskets in (110*7)/5=154 days

Solve 3
Suppose two persons are A and B.
A can do 1 work in 4 days, so in 1/4 work in 1 day. Similarly B can do 1/6 work in 1 day.
If they work together, then they can do 1/4 + 1/6 work in 1 day.
A+B = 1/4 + 1/6 work = 5/12 work in 1 day.
Now, in 1 day , 5/12 work
Therefore, in 12/5 days 5/12 * 12/5 = 1 work.
Total work done together is 1/(5/12) = 12/5 days
Answer: 12/5 days.

Solve 4
1st man 1 hour work = 1/3 hour
2nd man 1 hour work = 1/2
Now if they work together
Let the time be x hours
1x/3+1x/2=1
5x/6=1
X =6/5 hours

Solve 5
A and B can do a piece of work in 10 days.
Therefore A and B together can do 1/10 of work in one day.
A + B = 1/10…Eq..1
A alone can complete this work in 15 days. Thus A alone can do this work in 1/15.
Substituting the value of work done by A in Eq..1
A + B = 1/10
1/15 + B = 1/10
B = 1/10 - 1/15
B = (3 - 2)/30
B = 1/30
Thus, B can accomplish 1/30 of work in one day.
Accordingly, B alone could complete this work in 30 days.
Answer B alone could complete this work in 30 days.

Solve 6

Solve 7
A, B and C can cultivate a field in 10, 12 and 15 days respectively if they work together in how many days will they finish the work and what fraction of the work will each of them do

A, B और C क्रमशः 10, 12 और 15 दिनों में एक खेत में खेती कर सकते हैं यदि वे एक साथ कितने दिनों में काम करते हैं तो वे काम को कितने दिनों में पूरा करेंगे और उनमें से प्रत्येक का क्या अंश काम करेगा

Solve 8
A, B and C can do piece of work in 10 days
so they can do 1/10 part of work in a day
A alone can do same work in 40 days
so A can do 1/40 part of work in a day
B alone can do it in 30 days
so B can do 1/30 part of work in a day
let the days taken by C be x
1/10=1/40+1/30+1/x
1/10=7/120+1/x
1/10-7/120=1/x
12-7/120=1/x
5/120=1/x
1/24=1/x
therefore C can do 1/24 in a day
so C can do whole piece of work in 24 days

Solve 9
One day work of (A+B) = 1/8.
One day work of (B+C)= 1/12.
One day work of (A+B+C) =1/6.
Therefore one day work of C= 1/6–1/8 = 1/24.
And one day work of A = 1/6–1/12 = 1/12.
Thus , one day work of (A+C) = 1/12+1/24 = 1/8.
1/8 work A and C can complete in= 1 day.
1. work A and C can complete in= 1/(1/8).= 8 days. Answer.

Solve 10
Time taken by tap 1 to fill the cistern = 4h
work done in 1h = 1/4
time taken by tap 2 to fill the cistern = 3h
work done in 1 h = 1/3
one hour work of both taps = 1/4+1/3 =7/12
time taken by both taps to fill cistern =1÷7/12
=12/7 hours

Solve 12
first tap filled=1/12 min
second tap filled= 1/15 min
third tap =-1/10min
bath be filled if both taps are turned on = 1/12+1/15-1/10
=(5+4-6)60
=20 minutes

Solve 13
Let us call the pipe Pipe A.
Pipe A fills the cistern in 6 hrs
so in one hr Pipe A fills 1/6th of the cistern.
However with the leak it takes 7 hrs for Pipe A to fill the cistern.
Hence in one hour the cistern will have 1/7th left in.
So the difference between not leaking and leaking is 1/6 - 1/7 = 1/42 th of the cistern
this is amount of leak per hour.
Hence it will take 42 hours to fully empty the cistern
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Law's Of Motion

2020-01-17T13:52:00.000+05:30

Newton’s Laws of motion in Hindi : न्यूटन के गति के नियम भौतिक विज्ञान के अंतर्गत आनेवाले तीन सबसे अहम नियम हैं। न्यूटन लॉ किसी वस्तु पर लगने वाले बल और उस बल के कारण वस्तु की गति में हुए परिवर्तन के बीच सम्बन्ध बताते हैं।

न्यूटन के गति के इन तीनों नियमो को कई बार सिद्ध किया जा चुका हैं।

न्यूटन के गति के नियम – Newton’s laws of motion in Hindi

सर आइजक न्यूटन (Sir Isaac Newton) – वे एक भौतिक विज्ञानी तथा गणितज्ञ थे। इन्होने ही गुरुत्वाकर्षण के बारे में दुनिया को बताया था। न्यूटन ने गति के तीन नियम दिए है, जो इस प्रकार हैं।

न्यूटन का पहला नियम – यदि कोई वस्तु विरामावस्था(स्थिर अवस्था) में है तो वह तब तक विराम अवस्था में ही रहेगी जब तक उसपर कोई बाहरी बल न लगाया जायें, और गतिशील है तो तब तक एकसमान गति की अवस्था में रहेगी जब तक की उसपर बाहरी बल लगाकर उसे स्थिर न किया जाये

न्यूटन का दूसरा नियम – किसी भी वस्तु के संवेग परिवर्तन की दर उसपर लगाये गये बल के समानुपाती होती है, तथा संवेग परिवर्तन की दिशा वही होती है जो बल की दिशा होती है।

न्यूटन का तीसरा नियम – प्रत्येक क्रिया के बराबर तथा उसके विपरीत दिशा में प्रतिक्रिया होती है।

Exercise 8C

2020-01-15T14:32:00.000+05:30

Solution 1 =
Amount = Principal( 1 +r/100)^n
Rs 1323 = P (1+ 5/100)^2
Rs 1323= P ( 105/100)^2
Rs 1323 × 100/105 × 100/105 = Principal
Rs 1200 = Principal

Solution 2 =

Solution 3 =

Amount = Rs 1331
Time = 3/2 = 3 half years
Rate per annum = 20% = 10%

A = P( 1 + r/100 )^n
1331 = P ( 1 + 10/100 )^3
1331 = P( 110/100)^3
1331 × 100/110 × 100/110 × 100/110 = P
1000 Rs = Principle

Solution 4 =

S.I for 2 years = P*R*2/100

C.I for 2 years = P*[(1 + r/100)^2 - 1] = P(1 + 5/100)^2) - P = P(21/20)^2 - P

C.I - S.I for 2 years = 15

C.I - S.I = 441P/400 - P - 10P/100 = (441P - 400P - 40P)/400

15 = P/400

P= 400*15 = 6000 Rs.

Hence principal(sum of money) = Rs.6000

Solution 5 =

Solution 6 = (2)

P = Rs. 3136, n = 2 years. Compound interest = Rs. 345

Compound interest = Amount - Principal

Solution 7 =

Solution 8 =

Let the principal amount be ₹ P and the rate of interest be R% per annum.

For the interest compounded half yearly:

Time = 3/2 years = 2×3/2= 3years

Rate of interest (R%) = R/2

Given: amount at the end of 3 years must become to 216P/125

A= 216P/125

A= P(1+R/00)^n

216P/125= P ( 1+ R/200)³

216/125 = ( 1+ R/200)³

(6/5)³ = ( 1+ R/200)³

(6/5) = ( 1+ R/200)

6/5-1 = R/200

(6-5)/5 = R/200

1/5 = R/200

R= 200/5 = 40%

Hence, the rate of interest (R)= 40%

Solution 9 =

Exercise 8B

2020-01-15T14:24:00.000+05:30

Solution 1:

Amount=P(1+R/100)^n
=625(1+4/100)^2
=625*26/25*26/25
=676

CI=Amount-Principal
=676-625
=51

Solution 4:
Reena
Simple interest = principle × rate × time/100

Rate = 10%

Principle = 60000

Time = 3 years

Simple interest = 60000 × 3 × 0.1 = 18000

Rs 18000
Ruchira
Compound interest = Accumulated amount less the principle

Accumulated amount = P(1 + i)ⁿ

P = 50000

i = 10%

n = 3

A = 50000(1.1)³ = 66550

Compound interest = 66550 - 50000 = 16550

Rs 16550
Reena paid more interest by :
18000 - 16550 = 1450
Rs 1450

Solution 5:

P is 40960

R is 12.5% p.a semi annually

T is 1 1/2 years =3/2 years

A=p(1+r/200)^2n

=49130=amount

CI=A-P

=49130-40960

=8170Ans.

Solution 6:
Sudhir's Case

Principal = 2000
Rate = 10% p.a.
A = P ( 1 + r)n
100
A= 2000[ 1 + 10/100]1 = 2000 * 110/100
= 2200

Prashant's Case
Principal = 2000
Rate = 10% p.a. or 5% half - yearly
A = 2000 (1 + 5/100)2-no. of half years
= 2000 * 105/100 * 105//100
=2205
The Difference
2205 - 2200 = 5 rupees .
Hope this will help you .

Solution 7:

Case 1
Given : P = Rs. 16000, R = 5 %, T = 3/2 years
Simple Interest = (P*R*T)/100
= (16000*5*3)/(2*100)
Simple Interest = Rs. 1200
Case 2
Compound Interest
Given : P = Rs. 16000, R = 5 % per annum and compounded half yearly so, rate of interest = 2.5 %
T = 3/2 years = 1 year and one half year = 3 half years
A = P (1 +r/100)ⁿ
= 16000 (1 + 2.5/100)³
= 16000 × 102.5/100 × 102.5/100 × 102.5/100
A = Rs. 17230.25
So, compound interest = 17230.25 - 16000 = Rs. 1230.25
Difference between compound interest and simple interest = 1230.25 - 1200 = Rs 30.25
Answer.

Solution 8:
Principal (P)=10000.
Rate of compound interest (r)=12%.
No. Of years(n)=3years.

So Amount(A)=P[(1+r/100)^n].

=10000[1+12/100)^3].
= 10000[(112/100)^3].
= 10000*(112/100)*(112/100)*(112/100).
Upon solving this we get
A =14049.28
Interest = A- P.
=14049.28 - 10000.
= 4049.28Rs

Doudt 11 jan 2020

2020-01-11T14:40:00.000+05:30

Evaluate using algebraic formulas:-

Formula Sheet 2019

2019-12-09T15:17:00.003+05:30


  Formula Sheet

Publish Date: 10 Dec 2019
    

Author: Isha
    


Chapter 6


Chapter 9


Chapter 11


Chapter 12

Note: Click on Chapter Number to Read Formulas.

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Practise Test 1 on Sets Answer Sheet

2019-11-30T13:56:00.000+05:30

Answers for practice test on sets and subsets are given below to check the answers of the questions.

Answers:

1. C, D, E

2. (a) ⊄

(b) ⊂

(d) ⊂

(e) ⊂

(f) ⊂

3. (e)

4. (a) d, {3}

(b) d, {6}, {11}, {6, 11}

(d) d, {1}, {2}, {6}, {7}, {1, 2}, {1, 6}, {1, 7}, {2, 6}, {2, 7}, {6, 7}, {1, 2, 6}, {1, 2, 7}, {1, 6, 7}, {2, 6, 7}, {1, 2, 6, 7}

(e) {a}, {b}, {c}, {a, b}, {a, c}, {b, c}, {a, b, c}, d

(f) d

(g) d, {p}, {q}, {r}, {s}, {p, q}, {p, r}, {p, s}, {q, r}, {q, s}, {r, s}, {p, q, r } {p, q, s}, {p, r, s }, {q, r, s}, {p, q, r, s}

5. (a) d, {a}, {b}, {c}, {d}, {a, b}, {a, c}, {a, d}, {b, c}, {b, d}, {c, d}, {a, b, c}, {a, b, d}, {a, c, d}, {b, c, d}

(b) d, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}

(d) d, {5}, {10}

(e) d

(f) none

6. (a) 8

(b) 32

7. (a) 63
(b) 15

9. (a) {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

(b) {a, b, c, e, f, g}

(b) {1, 2, 4, 6, 8, 9, 10}

(b) True

(d) False

(e) True

(f) False

(g) False

(h) False

12. set of negative integers

13. (a) {0, 1, 2}

(b) {1, 2}

(b) No

(d) Yes

(e) No

(f) Yes

(g) Yes

(h) No

Practice Test 1 on Sets

2019-11-30T13:45:00.001+05:30

In practice test on sets and subsets we will solve 15 different types of question on sets and subsets.

1. If U = {1, 3, 5, 7, 9, 11, 13}, then which of the following are subsets of U.
A = {0}

B = {2, 4}

C = {1, 9, 5, 13}

D = {5, 11, 1}

E = {13, 7, 9, 11, 5, 3, 1}

F = {2, 3, 4, 5}

2. Let A = {2, 3, 4, 5, 6, 7} B = {2, 4, 7, 8) C = {2, 4}.

Fill in the blanks by ⊂ or ⊄ to make the resulting statements true.

(a) B __ A

(b) C __ A

(c) B __ C

(d) ∅ __ B

(e) C __ C

(f) C __ B

3. Which of the following sets is a universal set for the other four sets?
(a) The set of even natural numbers

(b) The set of odd natural numbers

(c) The set of natural numbers

(d) The set of negative numbers

(e) The set of integers

4. Write all the subsets for the following.
(a) {3}

(b) {6, 11}

(c) {2, 5, 9}

(d) {1, 2, 6, 7}

(e) {a, b, c}

(f) ∅

(g) {p, q, r, s}

5. Write down all the possible proper subsets for each of the following.
(a) {a, b, c, d}

(b) {1, 2, 3}

(c) {p, q, r}

(d) {5, 10}

(e) {x}

(f) ∅

6. Find the number of subsets for set
(a) containing 3 elements

(b) whose cardinal number is 5

7. Find the number of proper subsets of a set
(a) containing 6 elements

(a) containing 6 elements

(b) whose cardinal number is 4

8. Show with an example that if the number of elements in a set is ‘n’, then
(a) the number of subsets is 2n

(b) the number of proper subsets is 2n - 1.

9. Write the universal set for the following.
(a) P = {4, 6, 8} Q = {1, 3, 9} R = {0, 2, 5} S = {7}

(b) X = {a, b, c} Y = {c, b, f} Z = {e, g}

(c) Prime numbers less than 10, even numbers less than 10, multiples of 3 less than 10.

10. If ξ = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
A = {2, 4, 6, 8}

B = {3, 5, 7}

C = {1, 5, 7, 8, 9}

Find (a) A’ (b) B’ (c) C’

11. State whether true or false.
(a) Quadrilateral ⊆ polygon

(b) {1} ↔ {0}

(c) Whole numbers ⊆ natural numbers

(d) {a} ∈ {d, e, f, a}

(e) Natural numbers ⊆ whole numbers

(f) Integers ⊆ natural numbers

(g) 0 ∈ ∅

(h) ∅ ∈ {1 , 2, 3 }

12. Let the set of integer be the universal set and let A = set of whole numbers, then what is A’?

13. Let A {x : x = n — 2, n < 5}. Find A when
(a) n = W, n ∈ W

(b) n = N, n ∈ N

(c) n ∈ I = I

14. If U = {2, 3, 4, 5, 6, 7, 8, 9} X = {3, 5, 7, 9} Y = {2, 4, 6, 8}

Show that X = Y’ and Y = X’

15. Let P = {3, 5, 7, 9, 11} Q = {9, 11, 13} R = {3, 5, 9} S = {13, 11}

Write Yes or No for the following.

(a) R ⊂ P

(b) Q ⊂ P

(c) R ⊂ S

(d) S ⊂ Q

(e) S ⊂ P

(f) P ⊄ Q

(g) Q ⊄ R

(h) S ⊄ Q

Read Answer

What is Time ?

2019-11-23T12:20:00.001+05:30

time is what we want most but what we use worst

Time is passing non-stop, and we follow it with clocks and calendars. Yet we cannot study it with a microscope or experiment with it. And it is still passing. We cannot just say what actually happens as time passes.

Time is represented through changes, such as the circular motion of the Moon around the Earth. The passing of time is actually closely linked to the concept of space.

Relativity, according to the general theory of space or the universe, emerged in the Big Bang about 13.7 billion years ago. Prior to this, all cases were packed into one very small point. That point also contained what later came in the form of the Sun, Earth and Moon - heavenly bodies that tell us about the passage of time.

Before the Big Bang, there was no place or time.

Cosmology professor Kari Enkvist says, "In the theory of relativity, the concept of time starts with the Big Bang in the same way that latitude parallels start at the North Pole. You can't go more north than the North Pole."

One of the strangest properties of time is the fact that it is measured by speed and it also becomes apparent through motion.

According to the general theory of relativity, the evolution of space can result in the collapse of the universe. The whole matter will again shrink to a small point, ending the concept of time as we know it.

"The latest observations, however, do not support the idea of collapse, but rather inter-galactic distances increase at a faster rate," says the Enquistist.

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NewtronLearner

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Write a program to input an integer and check whether it is Armstrong or not, using do while loop.

Write a program to input an integer and check whether it is Pronic or not?

Write a program to input an integer and check whether it is Disarium or not?

Write a program to input time in seconds and display the time broken up as hours, minutes and seconds.

Write a program to input a floating point number and round it off to the nearest integer.

Write a program to input the Basic Pay of an employee and find the gross pay of the employee for the following allowances and deductions

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Give 2 examples of each of the following changes occurring during a chemical reaction : 1) Change of state of the reactants 2) Change of colour 3) Evolution of gas 4) Formation of precipitate Answer:

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What are oxides and its types with examples

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Chapter 18

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Surprise Test

Here is your answer

Let Sum be X then A =9X/4. T = 2 years. R = ?ATQ9X/4= X(1+R/100)*2 (3/2)*2= (1+R/100)*23/2 = 1+ R/100R/100 =3/2 - 1R =1/2(100)R = 50%

Heat Transfer

Solid can't be expand it have definite shape.

Exercise 13 (B)

Explanation:

Chemical Reactions

Exercise 10

Law's Of Motion

न्यूटन के गति के नियम – Newton’s laws of motion in Hindi

Exercise 8C

P = Rs. 3136, n = 2 years. Compound interest = Rs. 345 Compound interest = Amount - Principal

Exercise 8B

Doudt 11 jan 2020

Formula Sheet 2019

Practise Test 1 on Sets Answer Sheet

Practice Test 1 on Sets

What is Time ?

`Write a program to input an integer and check whether it is Armstrongor not, using do while loop.`

`Write a program to input an integer and check whether it is Pronic ornot?`

`Write a program to input an integer and check whether it is Disarium ornot?`

`Write a program to input three integers and checkwhether it forms Pythagorean triplet or not.`

Give 2 examples of each of the following changes occurring during a chemical reaction :

1) Change of state of the reactants

2) Change of colour

3) Evolution of gas

4) Formation of precipitate

Answer:

With the help of experiment, show the effect of heat on lime stone.

Let Sum be X then A =9X/4.
T = 2 years. R = ?
ATQ
9X/4= X(1+R/100)2
(3/2)2= (1+R/100)*2
3/2 = 1+ R/100
R/100 =3/2 - 1
R =1/2(100)
R = 50%

P = Rs. 3136, n = 2 years. Compound interest = Rs. 345

Compound interest = Amount - Principal