Deck 27: Energy, Work, and Power

Question 1

On heating a solid, as the separation of atoms increases the potential energy

A)decreases
B)remains constant
C)increases
D)becomes zero

Answer 1

increases

Question 2

Temperature can't be lower than

A)0 °C
B)0 °F
C)0 K
D)0 °R

Answer 2

0 K

Question 3

When a substance is melted, it's temperature doesn't rise because

A)energy is lost somewhere
B)energy is used to break the bonds
C)energy is used to make bonds
D)energy is absorbed to make bonds

Answer 3

energy is used to break the bonds

Question 4

As the object gains speed, it's G.P.E (Gravitational Potential Energy)

A)increases
B)remains constant
C)decreases
D)varies depending on altitude

Question 5

If energy loss is zero then decrease in G.P.E is equal to

A)decreases in kinetic energy
B)gain in kinetic energy
C)constant kinetic energy
D)zero kinetic energy

Question 6

Average power of all activities of our body is

A)111 W
B)113 W
C)116 W
D)120 W

Question 7

Change in G.P.E can be written as

A)mgh
B)mh
C)mg
D)gh

Question 8

Efficiency of car engine is only about

A)10%
B)20%
C)30%
D)80%

Question 9

Work is defined as

A)F × S
B)F × a
C)m × a
D)F × m

Question 10

Energy transferred to stone of weight 10 N falling from top of 250 m high cliff is

A)25000 J
B)250000 J
C)2500 J
D)250 J

Question 11

If force of 1 N moves an object through 1 m, then work done is

A)2 J
B)1 J
C)3 J
D)4 J

Question 12

SI units for energy and work are

A)Joules and kg
B)Joules and meter
C)Joules and newton
D)Joules

Question 13

If the ball is thrown upwards, the energy changings are

A)K.E changes to G.P.E
B)G.P.E changes to K.E
C)K.E changes to mechanical energy
D)mechanical energy changes to K.E

Question 14

1 W is equal to {{}}

A)10 J s^-1
B)1 J s
C)1 J s^-1
D)100 J s

Question 15

Work done by force of gravity on a satellite of 500 N at height is

A)0 J
B)1 J
C)2 J
D)3 J

Question 16

A weight-lifter raises weights with a mass of 200 kg from the ground to a height of 1.5 m, the increase in their G.P.E is

A)1962 J
B)2940 J
C)800 J
D)1000 J