JAMB Physics Past Questions & Answers - Page 91

451.

Calculate the electric field intensity between two plates of potential difference 6.5V when separated by a distance of 35cm.

A.

18.57NC\(^{-1}\)

B.

53.06N C\(^{-1}\)

C.

2.28NC\(^{-1}\)

D.

0.80NC\(^{-1}\)

Correct answer is A

Electric Field Intensity (E) = \(\frac{v}{d}\)

= \(\frac{\text{potential difference}}{\text{distance}}\)

= \(\frac{6.5v}{35cm}\)

= \(\frac{6.5}{35 \times 10^{- 2}}\)

= 18.57NC\(^{-1}\)

452.

Which of the following is not an electromagnetic radiation?

A.

x - ray

B.

Radio waves

C.

sunlight

D.

sound waves

Correct answer is D

Electromagnetic waves do not require any material medium, but sound waves is a mechanical wave that require a material medium

453.

Given that v, f and \(\lambda\) are the velocity, frequency and wavelength of a wave respectively. Which of the following equations is correct?

A.

v = f2\(\lambda\)

B.

f = \(\frac{v}{\lambda}\)

C.

f = \(\frac{v}{\lambda^2}\)

D.

\(\lambda = \frac{f}{v^2}\)

Correct answer is B

No explanation has been provided for this answer.

454.

A pressurized perfume bottle is left on the window pane of a room. What happens to he gas molecules of the perfume on a sunny day? They

A.

expand

B.

collide less often

C.

move more rapidly

D.

contract

Correct answer is C

No explanation has been provided for this answer.

455.

Which of the following statements is correct about the effect of dissolved salt on the freezing point of water?

A.

the freezing point is lowered

B.

the freezing point is increased

C.

there is no change in the freezing point

D.

the change in the freezing point depends on the temperature of the surrounding

Correct answer is A

No explanation has been provided for this answer.