Class 9 Science MCQ Work and Energy

Question :When a body falls freely towards the earth, then its total energy:
(a) increases
(b) decreases
(c) remains constant
(d) first increases and then decreases

Question :In case of negative work, the angle between the force and displacement is:
(a) 0°
(b) 45°
(c) 90°
(d) 180°

Question :Water stored in a dam possesses:
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy

Question :Which one of the following is not the unit of energy?
(a) Joule
(b) Newton meter
(c) Kilowatt
(d) Kilowatt hour

Question :A body is falling from a height h, After it has fallen a height $\frac{h}{2}$, it will possess:
(a) only potential energy
(b) only kinetic energy
(c) half potential and half kinetic energy
(d) more kinetic and less potential energy

Question :The capacity of a body to perform work is called:
(a) Energy
(b) Work
(c) Power
(d) Heat

Question :The rate of work done is called:
(a) Energy
(b) Power
(c) Capacity
(d) All of these

Question :The capacity to perform work is obtained from :
(a) Food
(b) Energy
(c) Power
(d) All of these

Question :An object of mass, m moving with velocity v has a kinetic energy of:
(a) $\frac{1}{2} m v^{2}$
(b) mgh
(c) $\frac{2 m}{v^{2}}$
(d) 2mv²

Question :The gravitational potential energy of an object of mass, m raised through a height, h from the earth’s surface is given by:
(a) $\frac{1}{2}$ mv²
(b) mgh
(c) $\frac{1}{2}$ mgh
(d) 2mgh

Question :If the displacement of the object is zero then the work done on an object by a force would be:
(a) 1 Joule
(b) 0.1 Joule
(c) 3.6 × 10⁶ Joule
(d) zero

Question :What is the energy possessed by an object due to its motion?
(a) Potential energy
(b) Electrical energy
(c) Kinetic energy
(d) None of them

Question : In case of negative work, the angle between the force and displacement is:
(a) 0°
(b) 45°
(c) 90°
(d) 180°

Question : When a body falls freely towards the earth, then its total energy
(a) Decreases
(b) Increases
(c) First increases and then decreases
(d) Remains constant

Question : A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done against the gravitational force will be (g = 10 ms²)
(a) 6 × 10³ J
(b) 6 J
(c) 0.6 J
(d) zero

Question : When a body falls freely towards the earth, then its total energy
(a) Decreases
(b) Increases
(c) First increases and then decreases
(d) Remains constant

Question : Which of the following does not possess the ability to do work not because of motion ?
(a) a sparrow flying in the sky
(b) a sparrow moving slowly on the ground
(c) a sparrow in the nest on a tree
(d) a squirrel going up a tree

Question : Which one of the following is not the unit of energy?
(a) Joule
(b) Newton meter
(c) Kilowatt
(d) Kilowatt hour

Question : The momentum of a bullet of mass 20 g fired from a gun is 10 kg m/s. The kinetic energy of this bullet in kJ will be:
(a) 25
(b) 2.5
(c) 0.25
(d) 5

Question : The work done on an object does not depend upon the
(a) displacement
(b) force applied
(c) angle between force and displacement
(d) initial velocity of the object

Question : Work done by a body is
(a) negative, positive or zero
(b) always positive
(c) always zero
(d) always negative

Question : The momentum of a bullet of mass 20 g fired from a gun is 10 kg.m/s. The kinetic energy of this bullet in kJ will be :
(a) 5
(b) 1.5
(c) 2.5
(d) 25

Question : The capacity of a body to perform work is called:
(a) Energy
(b) Work
(c) Power
(d) Heat

Question : A body is falling from a height h. After it has fallen to a height of h/2, it will possess:
(a) Only kinetic energy
(b) Half kinetic and half potential energy
(c) Only potential energy
(d) More kinetic and less potential energy

Question : If speed of a car becomes 2 times, its kinetic energy becomes
(a) 4 times
(b) 8 times
(c) 16 times
(d) 12 times

Question : When speed of the moving object is doubled its
(a) Acceleration is doubled
(b) Momentum becomes four times more
(c) K E. is increased to four times
(d) Potential energy is increased

Question : The capacity to perform work is obtained from :
(a) Food
(b) Energy
(c) Power
(d) All of these

Question : The work done on an object does not depend upon the:
(a) Angle between force and displacement
(b) Force applied
(c) Initial velocity of the object
(d) Displacement

Question : Work done by friction
(a) increases kinetic energy of body
(b) decreases kinetic energy of body
(c) increases potential energy of body
(d) decreases potential energy of body.

Question : What is the commercial unit of energy?
(a) electron volt
(b) W/s
(c) kW h
(d) joule

Question : What is the energy possessed by an object due to its motion?
(a) Potential energy
(b) Electrical energy
(c) Kinetic energy
(d) None of them

Question : A microphone converts:
(a) Sound energy into mechanical energy in stereo system
(b) Sound energy into electrical energy in public address system
(c) Electrical energy into sound energy in ordinary telephone
(d) Microwave energy into sound energy in a mobile phone

Question : One joule work is said to be done when
(a) a force of 1 N displaces a body by 1 cm
(b) a force of 1 N displaces a body by 1 m
(c) a force of 1 dyne displaces a body by 1 m
(d) a force of 1 dyne displaces a body by 1 cm.