JAMB Physics Past Questions & Answers - Page 33

161.

In an elastic collision, momentum is conserved as well as well as?

A.

velocity

B.

kinetic energy

C.

potential energy

D.

speed

Correct answer is B

An elastic collision is an encounter (collision) between two bodies in which the total kinetic energy of the two bodies remains the same.

162.

Which of the following quantities is a vector?

A.

Volume

B.

Momentum

C.

Energy

D.

Speed

Correct answer is B

No explanation has been provided for this answer.

163.

The time rate of increase in velocity is called

A.

force

B.

momentum

C.

acceleration

D.

speed

Correct answer is C

No explanation has been provided for this answer.

164.

A substance has half of 3 min. After 6 min, the count rate was observed to be 400. What was its count rate at zero time? 

A.

1600

B.

1200

C.

200

D.

2400

Correct answer is A

Let the count rate at zero time be N 

N \(\frac{3 min}{\to}\)  \(\frac{N}{2}\) \(\frac{3 min}{\to}\) \(\frac{N}{4}\)

\(\frac{N}{4}\) 

= 400

N = \(\frac{400}{N/4}\) x N 

= 1600

165.

Which of the following pairs is part of the electromagnetic spectrum? 

I. Radio waves

II. sound waves

III. Gamma rays

IV. water waves

A.

I and II

B.

III and IV

C.

I and III

D.

II and IV

Correct answer is C

Examples of electromagnetic waves are radio waves, X-rays, gamma rays, light rays, etc