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WAEC Physics Past Questions & Answers - Page 309

1,541.

Which of the following surfaces will radiate heat energy best?

A.

Red

B.

White

C.

Black

D.

Yellow

E.

Blue

Correct answer is C

No explanation has been provided for this answer.

1,542.

A thermometer has its stem marked in millimeter instead of degree Celsius. The lower fixed point is 30mm and the upper is 180mm. Calculate the temperature in degree celsius when the thermometer reads 45mm.

A.

67.5oC

B.

30.0oC

C.

25.0oC

D.

15.0oC

E.

10.0oC

Correct answer is E

θ = (x/y) x 100.
where x = UFP -LFP -another scale, and y = UFP - LFP for celsius scale.

=> {(45-30)/(180-30)} x 100 = 10.0oC

1,543.

An engine raises 1000kg of water through a height of 60m in 20s. What is the power of the engine? (Take g = 10ms-2>).

A.

120,000 W

B.

30,000 W

C.

333 W

D.

300 W

E.

30 W

Correct answer is B

P = mgh/t = (1000 × 10 × 60) ÷ 20 = 30,000 W.

1,544.

Which of the following is a derived unit?

A.

Metre

B.

Coulomb

C.

Kilogram

D.

Second

E.

Ampere

Correct answer is B

No explanation has been provided for this answer.

1,545.

The motion of the prongs of the sounding tuning fork is

A.

random

B.

translational

C.

rotational

D.

vibratory

E.

vibratory and rotational

Correct answer is D

No explanation has been provided for this answer.