WAEC Past Questions and Answers - Page 3233

16,161.

A transverse wave can be distinguished from a longitudinal wave by

A.

diffraction

B.

reflection

C.

refraction

D.

polarization

Correct answer is D

No explanation has been provided for this answer.

16,162.

The quality of a note depends on its

A.

frequency

B.

pitch

C.

overtones

D.

amplitude

Correct answer is C

No explanation has been provided for this answer.

16,163.

A car traveling at 30ms\(^{-1}\) overcomes a frictional resistance of 100N while moving. Calculate the power developed by the engine. [1 hp = 0.75 kW]

A.

0.23hp

B.

0.40hp

C.

4.00hp

D.

4.40hp

Correct answer is C

P = FV = \(\frac{100 \times 30}{1000} = 3 kW\)

\(\frac{3}{0.75} = 4hp\)

16,164.

The mass of an empty density bottle is 30g. When filled with a liquid, the mass of the bottle and the liquid is 40g. On heating the filled bottle through 40ºc, the mass reduces to 38g. Calculate the apparent cubic expansivity of the liquid

A.

6.25 x 10K-1

B.

6.25 x 10-3K-1

C.

2.50 x 10-3K-1

D.

2.50 x 10-4K-1

Correct answer is B

Apparent cubic expansivity = \(\frac{\text{mass of hot liquid expelled}}{\text{mass of hot liquid left x temp. rise}}\)

= \(\frac{2}{8 \times 40} = 0.00625\)