JAMB Physics Past Questions & Answers - Page 338

1,686.

The magnification of an object 2cm tall when placed 10cm in front of a plane mirror is

A.

6.0

B.

1.0

C.

0.7

D.

0.6

Correct answer is B

M = v = \(\frac{2}{2}\) = 1

1,687.

A pinhole camera is placed 300m in front of a building so that the image is formed on a screen 5cm from the the pinhole. If the image is 2.5cm high, the height of the building will be

A.

25m

B.

50m

C.

100m

D.

150m

Correct answer is D

==> \(\frac{v}{u}\) = \(\frac{hi}{ho}\)

==> \(\frac{5}{300}\) = \(\frac{2.5}{ho}\)

= 150m

1,688.

Where can a man place his face to get an enlarged image when using a concave mirror to shave?

A.

Between the centre of curvature and the principal focus

B.

At the principal focus

C.

Between the principal focus and the pole

D.

At the centre of curvature

Correct answer is C

No explanation has been provided for this answer.

1,689.

The characteristic of a vibration that determines its intensity is the

A.

Frequency

B.

Overtone

C.

Wavelength

D.

Amplitude

Correct answer is D

No explanation has been provided for this answer.

1,690.

Which of the following factors will affect the velocity of sound?

A.

An increase in the pitch of the sound

B.

An increase in the loudness of the sound

C.

Wind travelling in the same direction of the sound

D.

A change in the atmospheric pressure at constant temperature

Correct answer is C

No explanation has been provided for this answer.