# Work, Power and Energy MCQ’S Class 9

## Chapter-11 : Science Class 9 MCQ’s with Answers

Q1. Work done is measured by:
(a) force x distance
(b) mass x velocity
(c) force x energy
(d) none of the these

Ans: Force x distance

Q2. Joule is the unit of:
(a)Mass
(b) Work
(c) Energy
(d) Velocity

Ans: work

Q3. A body at rest can have:
(a) Energy
(b) Power
(c) Momentum
(d) Velocity

Ans: Energy

Q4. Newton-metre is the unit of:
(a) Speed
(b) Energy
(c) Gravitational intensity
(d) Work

Ans: Work

Q5. Ns is equivalent to
(a)Nm-1s
(b) kg ms-1
(c)kg ms-2
(d)kg ms-3

Ans: kg ms-1

Q6. Kg m2s-2 is associated with
(a) Work
(b) Speed
(c) Energy
(d) Momentum

Ans: Energy

Q7.A flying aeroplane possesses
(a)Only potential energy
(b) Only kinetic energy
(c) Both potential and kinetic energy
(d) None of these

Ans: Both potential and kinetic energy

Q8.The kinetic energy of a body is increased most by doubling its:
(a) Speed
(b) Density
(c) Weight
(d) Mass

Ans: Speed

Q9. A wound watch spring has:
(a)No energy stored in it
(b) Mechanical P.E. stored in it
(c) Mechanical K.E. stored in it
(d) None of these

Ans: Mechanical P.E. stored in it

Q10. In the oscillation of a simple pendulum, the sum of the P.E.andK.E. is:
(a) constant
(b) Minimum
(c) Maximum
(d) Infinitive

Ans: Constant

Q11. When the speed of a moving object is doubled, its:
(a) Weight is doubled
(b) Kinetic energy increased four times
(c) Kinetic energy is doubled
(d) None of these

Ans: Kinetic energy increased four times

Q12. The kinetic energy of the body decrease by 10% what is the percentage decreases in momentum
(a) 50
(b) 40
(c) 30
(d) None of these

Ans: None of these

Q13.The kinetic energy of a body decreases by 36% what is the percentage decrease in momentum
(a) 18
(b) 19
(c) 20
(d) 21

Ans: 20

Q14. The mass of a body P is twice that of body Q.,but the speed of half of that of Q. The Kinetic energies of p and q are in the ratio of
(a) 1 : 2
(b) 2 : 1
(c) 1 : 4
(d) 4 : 1

Ans: 1 : 2

Q15. A photocell converts light energy into:
(a) Physical energy
(b) chemical energy
(c) electrical energy
(d) heat energy

Ans: electrical energy

Q16. When the time is taken to complete a given amount of work increases
(a) energy increases
(b) power increases
(c) power decreases
(d) energy decreases

Ans: power decrease

Science MCQ’S