NECO Physics Past Questions & Answers - Page 17

81.

A box is pulled a distance s along a smooth horizontal floor by a force of magnitude F, inclined at an angle θ to the horizontal. The work done is

A.

Fs cos θ

B.

Fs cosec θ

C.

Fs sec θ

D.

Fs sin θ

E.

Fs tan θ

Correct answer is A

No explanation has been provided for this answer.

82.

Which of the following will reduce the frequency of oscillation of a simple pendulum?

A.

Decreasing the length of the string

B.

Increasing the amplitude of oscillation

C.

Increasing the length of the string

D.

Increasing the mass of the bob

E.

Reducing the mass of the bob.

Correct answer is C

No explanation has been provided for this answer.

83.

Which of the following statements is correct?

A.

Alpha particles have a large mass and high penetrating power

B.

Alpha particles have a small mass and a low penetrating power

C.

Beta partials have no mass and a high penetrating power

D.

Beta particles have a large mass and a low penetrating power

E.

Gamma rays have no mass and a high penetrating power

Correct answer is E

No explanation has been provided for this answer.

84.

The charge of an alpha particle can be neutralized by

A.

1 beta particle

B.

2 photons of gamma rays

C.

2 beta particles

D.

4 beta particles

E.

4 photons of gamma rays

Correct answer is C

No explanation has been provided for this answer.

85.

Which of the following is used for shielding radioactive fallout?

A.

Aluminum

B.

Lead

C.

Iron

D.

Plastic

E.

Wood

Correct answer is B

No explanation has been provided for this answer.