Work-Energy Theorem NEET Questions

Work-Energy Theorem MCQ Questions

1.
The work-energy theorem states that:
A.
Total energy of a body is always constant
B.
Change in kinetic energy of a body equals the work done on it by the net force
C.
Work done by a force equals force times time
D.
KE equals work done only when body starts from rest
ANSWER :
B. Change in kinetic energy of a body equals the work done on it by the net force
2.
Mathematically, the work-energy theorem is expressed as:
A.
Kf + Ki = W_net
B.
Kf − Ki = W_net
C.
W_net = œmv²
D.
ΔK = −W_net
ANSWER :
B. Kf − Ki = W_net
3.

A body of mass 1 kg is moving with a velocity of 10 m/s. A constant force acts on it for 4 seconds, increasing its velocity to 20 m/s. The work done by the force over this period is:

NEET - 2015

A.

100 J

B.

150 J

C.

200 J

D.

250 J

ANSWER :

B. 150 J

4.

The work-energy theorem for constant force is derived from:

A.

Conservation of momentum

B.

Newton's Second Law (F = ma) combined with kinematics (v² − u² = 2as)

C.

Conservation of energy

D.

Newton's Third Law

ANSWER :

B. Newton's Second Law (F = ma) combined with kinematics (v² − u² = 2as)

5.

For 3-dimensional motion under constant force, the work-energy theorem is obtained by:

A.

Using conservation of momentum in 3D

B.

Using v² − u² = 2a·d (vector form), then multiplying by m/2 to get F·d = ΔKE

C.

Using v² − u² = 2as in x-direction only

D.

Integrating Newton's 2nd Law over time

ANSWER :

B. Using v² − u² = 2a·d (vector form), then multiplying by m/2 to get F·d = ΔKE

6.
The work-energy theorem is related to Newton's Second Law in that:
A.
They are completely independent principles
B.
WE theorem is the vector form of Newton's 2nd Law
C.
WE theorem is the scalar (integral) form of Newton's 2nd Law — temporal information is integrated over
D.
WE theorem is more general than Newton's 2nd Law
ANSWER :
C. WE theorem is the scalar (integral) form of Newton's 2nd Law — temporal information is integrated over