WAEC Physics Past Questions & Answers - Page 138

686.

A dry plastic comb used in combing hair was found to attract pieces of paper and dust. The most probable explanation for this phenomenon is that the comb has been given

A.

magnetization by induction

B.

electric charges by induction

C.

electric charges by conduction

D.

electric charges by friction

Correct answer is D

No explanation has been provided for this answer.

687.

Which of the following statements about sound wave is not correct? Sound waves can be

A.

reflected

B.

refracted

C.

diffracted

D.

polarized

Correct answer is D

No explanation has been provided for this answer.

688.

A sounding tuning fork is brought near the open end of a pipe containing air and the loudness of the sound is observed to increase. This observation is due to

A.

an echo

B.

resonance

C.

interference

D.

reverberation

Correct answer is B

No explanation has been provided for this answer.

689.

Which of the following factors can affect the speed of sound in air?

i. The temperature of the surrounding
ii. The direction of the wind
iii. The pitch of the sound.

A.

i and ii only

B.

ii and iii only

C.

i and iii only

D.

i, ii and iii

Correct answer is A

No explanation has been provided for this answer.