Conservation of Energy and Power, Class 9 Science

1. There will be total 10 MCQ in this test.
2. Please keep a pen and paper ready for rough work but keep your books away.
3. The test will consist of only objective type multiple choice questions requiring students to mouse-click their correct choice of the options against the related question number.
4. No negative marking for incorrect choice.
5. Please click on “Finish the Test” when you want to exit.
6. All the best – Happy Studying

1. What is the commercial unit of energy?

  electron volt

 W/s

  kW h

 joule

Question 1 of 10

2. A stone weighing 1 kg is dropped from rest from a height of 4 metres above the ground. When it has free-fallen 1 metre its total energy with respect to the ground is

 15 J

 40 J

 20 J

 30 J

Question 2 of 10

3. A lamp consumes 1000J of energy in 10s, what is its power?

 100 W

 100000W

  1kW

  1000 W

Question 3 of 10

4. When we throw a rock from the top of a building which equation describes the energy of the body at each pint during the fall?

 A

 B

 C

 D

Question 4 of 10

5. What is not true about energy?

  Energy can be created.

  Energy can move from one object to another

 Energy can be stored.

 Energy can be transformed from one type of energy to another type of energy.

Question 5 of 10

6. If work is done at a faster rate, then

 power is more

 No power is required to do work

 power is less

  Infinite power is required

Question 6 of 10

7. A diesel engine supplies 25,000 J of energy in 50 seconds. Power of engine would be

  7500 W

 250 W

 25000 W

 500 W

Question 7 of 10

8. How much energy does a 150 W steam iron consume per second?

 15 J

 0.15 J

 150 J

 15 watt

Question 8 of 10

9. A ball is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy when its reaches the maximum height?

 Kinetic energy is double

 Kinetic energy is zero

 Kinetic energy is maximum at maximum height

 Kinetic energy is half of initial value

Question 9 of 10

10. A girl weighing 45 kg jumps to a height of (1/2) m at the rate 10 times per minute. The power at which she is spending the energy is:

 25 W

 75 W

 50 W

 100 W

Question 10 of 10

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