Question

A. Objective Questions

1. Write true or false for each statement

(a) A coolie does no work against the force of gravity while carrying a luggage on a road

(b) The energy stored in water of a dam is the kinetic energy.

(c) The energy of a flying kite is kinetic energy.

(d) Work done by a boy depends on the time in which he does work.

(e) Power spent by a body depends on the time for which it does work.

2. Fill in the blanks:

(a) Work is said to be done by a forte only when _________

(b) Work done = Force x _________

(c) The energy of a body is its capacity to do ________

(d) The S.I. unit of energy is _______

(e) The potential energy is due to its _________ n and kinetic energy of body is due to its _________

(f) Gravitational potential energy U = mass × force of gravity on unit mass × ________

(g) Kinetic energy = ½ × mass × _______

(h) Power P = ______ /time taken

(i) The S. I. unit of power is ________

(j) I.H.P. = _______

Select the correct alternative

(a) The S.I. unit of work is

1. second 2. metre 3. joule 4. Newton

(b) No work is done by a force if the body

1. moves in direction of force

2. does not move

3. moves in opposite direction

4. none of the these

(c) Two coolies A and B do some work in time 1 minute and 2 minute respectively. The power spent is

1. same by both coolies 2. is more by coolie A than by B

3. is less by coolie A than by B 4. nothing can be said.

(d) The expression of power P is

1. P=mgh 2. P=P=1/22

3. P=F×d 4. P=F×d/t

(e) 1 H.P is equal to 1.

1 W

2. 1 J

3. 746 J

4. 746 W

(f) When a boy doubles his speed, his kinetic energy becomes

1. half

2. Double

3. four times

4. no change

(g) A boy lifts a luggage from height 2 m to 4 m. The potential energy will become

1. half

2. double

3. one-third

4. one-fourth



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Answer 1

Explanation:

1 (a) True

(b) False

(c) True

(d) False

(e) True

Hope it helps you!!

Answer 2

Answer:

a true

b. true

c. false

d. true

2b. accelerate

c. work

d. joule

e. position and. height

f. mgh

g. velocity

h. energy

3a. 3

b. 4

c. 3

d. 4

e. 4

f. 2

g. 2