NECO Physics Past Questions & Answers - Page 51

251.

Which is NOT one of the laws of solid friction?

A.

The frictional force between two surfaces opposes their relative motion

B.

The ratio of frictional force to the normal reaction varies for two given surfaces

C.

The ratio of frictional force to the normal reaction is constant for two given surfaces

D.

The limiting frictional force is independent of the area of surface in contact.

E.

Dynamic frictional force is independent of the relative velocity of the surfaces in contact.

Correct answer is B

No explanation has been provided for this answer.

252.

An electron of charge a = 1.6 × 10-19C is situated in a uniform electric field of intensity 2.4 × 105 V m-1. What is the force on the electron?

A.

1.60 × 10-19N

B.

3.84 × 1019N

C.

1.92 × 10-14N

D.

3.84 × 10-14N

E.

7.68 × 10-14N

Correct answer is D

No explanation has been provided for this answer.

253.

Which statement is TRUE of a block of stone of mass m, with zero momentum?

A.

The acceleration of the stone is non-uniform

B.

The stone is stationary

C.

The stone moves at a constant velocity

D.

The stone moves with maximum velocity

E.

The stone moves with minimum velocity.

Correct answer is B

No explanation has been provided for this answer.

255.

The falling of light energy on a metal such that electrons are liberated from the metal is called

A.

electron effect

B.

metal electron effect

C.

metal emission

D.

photoelectric effect

E.

photoemission

Correct answer is E

No explanation has been provided for this answer.