NECO Physics Past Questions & Answers - Page 16

76.

An electric motor primary converts

A.

electrical energy to chemical energy

B.

electrical energy to heat energy

C.

electrical energy to mechanical energy

D.

mechanical energy to electrical energy

E.

mechanical energy to light energy

Correct answer is C

No explanation has been provided for this answer.

77.

Which of the following statements is/are correct? Sound waves travel through

I. air
II. vacuum
III.Water

A.

II only

B.

I and II only

C.

II and III only

D.

I and III only

E.

I, II, and III

Correct answer is D

No explanation has been provided for this answer.

78.

Which of the following radiations has the shortest wavelength?

A.

Infrared rays

B.

Light waves

C.

Microwaves

D.

Ultraviolet rays

E.

X-rays

Correct answer is E

No explanation has been provided for this answer.

79.

Which of the following is/are longitudinal wave(s)?

I. Light waves from the sun
II. Sound waves in the air
III. Waves on a vibrating string

A.

I only

B.

II only

C.

I and II only

D.

I and III only

E.

II and III only

Correct answer is B

No explanation has been provided for this answer.

80.

A radio station broadcasts at a frequency of 400KHz. If the speed of the wave is 3.0 ×10-8 ms-1, calculate the wavelength of the radio wave.

A.

1.3 × 102m

B.

3.0 × 102m

C.

2.4 × 102m

D.

5.0 × 102m

E.

7.5 × 102m

Correct answer is E

No explanation has been provided for this answer.