Sustainable development is "development that meets the needs of the present without compromising the ability of future generations to meet their needs". It is a continuous process, not an event. Sustainability refers to the use of resources in a way that satisfies human needs while conserving the environment, so that these needs can continue to be satisfied not only for the present, but also for future generations.
The main features of sustainable ...

NCERT Exemplar Solutions for Chapter 1 Chemical Reactions and Equations Class 10 Science
Short Answer Type Questions
1. Write the balanced chemical equation for the following equations for the following reaction and identify the type of reaction in each case.
(a) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 K to form ammonia gas.
(b) Sodium hydroxide solution is treated with acetic acid to form sodium acetate a

Online Test of Chapter 11 Work Energy and Power 2 Science| Class 9th
1. The kinetic energy of a body changes from 12 J to 60 J due to the action of a force of 5N on an object of mass 4 kg. The work done by the force is:
(i) 36 J
(ii) 60 J
(iii) 48 J
(iv) 24 J
2. Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of velocities with which they are traveling is :
(i) 3:4
(ii) 1:2
(iii) 4:5
(iv) 2:1
3. If the speed of an object do

Online Test of Chapter 11 Work Energy and Power 1 Science| Class 9th
1. A body is acted upon by a force 25 N acquires of 2.5 ms-2 and covers a distance of the force. If the body starts from rest, the Kinetic energy acquired by it is?
(i) 75 J
(ii) 25 J
(iii) 250 J
(iv) 100 J
2. A freely falling body during its fall will have
(i) Kinetic energy
(ii) Potential energy
(iii) Sound energy
(iv) Both kinetic energy and potential energy
3. A boy climbs on to a

Online Test of Chapter 9 Force and Laws of Motion 2 Science| Class 9th
1. According to Newton’s third law of motion, action and reaction
(i) always act on the same body
(ii) always act on different bodies in opposite direction
(iii) have same magnitudes and direction
(iv) act on either body at normal to each other
2. The minimum number of unequal forces that can make zero resultant is
(i) two
(ii) three
(iii) four
(iv) ten
3. An object of mass 2 kg is sl

Online Test of Chapter 9 Force and Laws of Motion 1 Science| Class 9th
1. An unbalanced force is necessary for an object to be
(i) at reset
(ii) in motion with a constant velocity
(iii) accelerated
(iv) all of the preceding
2. Bags at the top of a school van are tied using a string to avoid the effect of
(i) inertia
(ii) momentum
(iii) force
(iv) acceleration
3. Inertia
(i) sets objects in motion
(ii) causes changes in motion
(iii) is the result of a net

Chapter 15 Probability- MCQ Online Test 2 Class 9 Maths
1. One card is drawn from a well-shuffled deck of 52 cards. The probability of drawing an ace is
(a) 1/13
(b) 1/17
(c) 12/13
(d) 5/13
2. The sum of the probabilities of All events of a trial is
(a) between 0 and 1
(b) 1
(c) 0
(d) greater than 1
3. A and B throw a pair of dice. If A throws 9, then B’s chance of throwing a higher number is
(a) 1/6
(b) 5/6
(c) 5/16
(d) 2/9
4. Probability of selecting

Chapter 15 Probability- MCQ Online Test 1 Class 9 Maths
1. The probability of an impossible event is
(a) less than 1
(b) more than 1
(c) 0
(d) 1
2. In a cricket match, a batswoman hits the boundary 6 times out of 30 balls played by her. Find the probability that she did not hit a boundary is
(a) 4/25
(b) 14/15
(c) 24/30
(d) 12/25
3. A die is thrown 300 times and odd numbers are obtained 153 times. Then, the probability of getting an even number is
(a) 14

Chapter 13 Surface Areas and Volumes- MCQ Online Test 2 Class 9 Maths
1. The total surface area of a cube is 96cm2.
(a) 68 cm3
(b) 60 cm3
(c) 64 cm3
(d) 65 cm3
2. If the outer diameter of a pipe 21 m long is 1 m, then its curved surface area is
(a) 56 m2
(b) 60m2
(c) 62 m2
(d) 66 m2
3. A cube of side 4 cm contains a sphere touching its sides. Find the approximate volume of the gap in between.
(a) 30.48 cm3
(b) 35.18 cm3
(c) 33.40 cm3
(d) 38.41 cm3
4. Th

Chapter 13 Surface Areas and Volumes- MCQ Online Test 1 Class 9 Maths
1. A rectangular sand box is 5 m wide and 2 m long. How many cubic metres of sand are needed to fill the box upto a depth of 10 cm ?
(a) 100
(b) 10
(c) 1
(d) 1000
2. A beam 9 m long, 40 cm wide and 20 cm deep is made up of iron which weighs 50 kg per cubic metre. The weight of the beam is :
(a) 47 kg
(b) 33 kg
(c) 30 kg
(d) 36 kg
3. The maximum length of a pencil that can be kept in a