NEET Physics Work Energy and Power MCQs Set A

a) the magnetic forces do not work on each particle

b) the two magnetic forces are equal and opposite, so they produce no net effect

c) the magnetic forces do equal and opposite (but nonzero) work on each particle

d) the magnetic forces are necessarily negligible

Answer: the magnetic forces do not work on each particle

Question: A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is

a) more for the case of a positron, as the positron moves away a larger distance

b) less for the case of a positron, as the positron moves away more rapidly and the force on it weakens

c) same as the same force law is involved in the two experiments

d) same as the work done by charged particle on the stationary proton

Answer: more for the case of a positron, as the positron moves away a larger distance

Question: A man squatting on the ground gets straight up and stand. The force of reaction of ground on the man during the process is

a) at first greater than mg and later becomes equal to mg

b) variable but always greater than mg

c) constant and greater than mg in magnitude

d) constant and equal to mg in magnitude

Answer: at first greater than mg and later becomes equal to mg

Question: A bicyclist comes to a skidding stop in 10 m. During this process, the force on the bicycle due to the road is 200N and is directly opposed to the motion. The work done by the cycle on the road is

a) zero

b) + 2000 J

c) – 200 J

d) – 20,000 J

Answer: zero

Question:  A body is falling freely under the action of gravity alone in vaccum. Which of the following quantities remain constant during the fall?

a) Total mechanical energy

b) Total linear momentum

c) Potential energy

d) Kinetic energy

Answer: Total mechanical energy

Question:  During inelastic collision between two bodies, which of the following quantities always remain conserved?

a) Total linear momentum

b) Speed of each body

c) Total mechanical energy

d) Total kinetic energy

Answer:  Total linear momentum

Question: Two inclined frictionless tracks, one gradual and the other steep meet at A from where two stones are allowed to slide down from rest, one on each track as shown in figure. Which of the following statement is correct?

a) Both the stones reach the bottom with the same speed and stone II reaches the bottom earlier than stone I

b) Both the stones reach the bottom at different times and with different speeds

c) Both the stones reach the bottom with the same speed and stone I reaches the bottom earlier than stone II

d) Both the stones reach the bottom at the same time but not with the same speed

Answer:  Both the stones reach the bottom with the same speed and stone II reaches the bottom earlier than stone I

Question:

a) V = E, K = O

b) V = O, K < E

c) V = O, K = E

d) V < E, K = O

Answer:  V = E, K = O

Question:

a)

b)

c)

d) None of these

Answer:

More Questions............................................

Question:

a) 50 J

b) 10 J

c) 100 J

d) None of these

Answer: 50 J

Question:  A body is moving unidirectionally under the influence of a source of constant power supplying energy. Which of the diagrams shown in figure correctly shown the displacementtime curve for its motion?

a)

b)

c)

d)

Answer:

Question:  Which of the diagrams shown in figure most closely shows the variation in kinetic energy of the earth as it moves once around the sun in its elliptical orbit?

a)

b) None of these

c)

d)

Answer:

Question:  Which of the diagrams shown in figure represents variation of total mechanical energy of a pendulum oscillating in air as function of time?

a)

b)

c)

d)

Answer:

Question:  A mass of 5 kg is moving along a circular path of radius 1 m. If the mass moves with 300 rev/min, its kinetic energy would be

a)

b)

c)

d) 0

Answer:

Question:    A raindrop falling from a height h above ground, attains a near terminal velocity when it has fallen through a height (3/4)h. Which of the diagrams shown in figure correctly shows the change in kinetic and potential energy of the drop during its fall up to the ground?

a)

b)

c)

d)

Answer:

Question:   In a shotput event an athlete throws the shotput of mass 10 kg with an initial speed of 1 m s^–1 at 45° from a height 1.5 m above ground. Assuming air resistance to be negligible and acceleration due to gravity to be 10 m s^–2, the kinetic energy of the shotput when it just reaches the ground will be

a) 155.0 J

b) 5.0 J

c) 52.5 J

d) 2.5 J

Answer:  155.0 J

Question:  Which of the diagrams in figure correctly shows the change in kinetic energy of an iron sphere falling freely in a lake having sufficient depth to impart it a terminal velocity?

a)

b)

c)

d)

Answer:

Question:    A cricket ball of mass 150 g moving with a speed of 126 km/ h hits at the middle of the bat, held firmly at its position by the batsman. The ball moves straight back to the bowler after hitting the bat. Assuming that collision between ball and bat is completely elastic and the two remain in contact for 0.001s, the force that the batsman had to apply to hold the bat firmly at its place would be

a) 1.05 × 10⁴ N

b) 10.5 N

c) 21 N

d) 2.1 × 10⁴ N

Answer:  1.05 × 10⁴ N

Question:  A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is :

a)

b) 2 mv²

c) 4 mv²

d) mv²

Answer: 

Question:  If the linear momentum is increased by 5%, the kinetic energy will increase by

a) 10%

b) 100%

c) 50%

d) 125%

Answer:  10%