NCERT Class 9 Physics Formative Assessment of Work and Energy CBSE Board Sample Problems

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Short Answer Based questions

1) What is unit of energy?

2) The total energy when a body falls freely towards earth remains constant. True or false?

3) What do you mean by kinetic energy of the body?

4) If the mass of the body is doubled and velocity is made halved, the kinetic energy will become?

5) Potential energy is a vector quantity True or false?

6) When the force acts at right angle to the direction of motion, what is the work done by the force

7) What is Power?

8) What is Law of conservation of energy?

Match the column

Match the column
Column A (Energy Conversion)	Column B (Converters)
Chemical energy into Mechanical energy	Electric Generator
Heat energy into Mechanical engine	Electric Motor
Mechanical energy into Electrical energy	Car engine
Electrical energy to Mechanical energy	Steam engine
Light energy into electrical energy	Electric bulb
Electrical energy into light energy	Solar Cell

Table type question

A force 10 N act on the body and body is displaced by 10 m. The angle between force and displacement are given below. Calculate the work done

Table type question
Angle	30	45	60	90
Work done	?	?	?	?

Table type question

A body of mass 10 kg falls from the height 10 m towards the earth. Given g=10m/

Table type question
Height from earth(m)	10m	?	?	2m
Potential energy(J)	?	?	500J	?
Kinetic energy (J)	?	1000J	?	?
Mechanical energy (J)	?		?	?

Fill in the blanks

1) 1 Kilo Watt hour of energy is equal to ____Joule

2) Power is the rate of doing____ and its unit is ____

3) Work done by the force can be ____and ____

4) The water stored in the reservoir of the tank possessed _____energy

5) The total energy of the swinging pendulum remains_____ at all the points

6) When the body falls freely towards earth, potential energy of the body ______while kinetic energy of the body _____. The total remains _____at all the point during the motion

Solution:

2) Work, watt

3) Negative, zero, positive

4) Potential

5) Constant

6) Decrease, increase, constant

Crossword Puzzle

Across

2. The scientist with whom unit of power is named

5. The kinetic energy of the body depends on mass and this quantity

7. The energy possessed by the car moving on the road

8. The Bigger unit of power

9. Work and power are these quantities

Solution:

Across

James, velocity, kinetic, kilowatt, scalar

Down

1. The work done by the earth on the satellite moving in circular path

3. Solar water heater converts this energy into heat energy

4. The gravitation potential energy is present because of this

6. In hydroelectric power house, the potential energy of the water is finally transformed to this energy

Solution

Down

Zero, light, Position, electrical