WAEC Physics Past Questions & Answers - Page 85

421.

The volume of a given mass of gas at 27oC and 800 mmHg is 76cm2. Calculate its volume at s.t.p

A.

100.0 cm3

B.

72.8 cm3

C.

60.0 cm3

D.

36.4 cm3

Correct answer is B

\(V_2 = \frac{P_1V_1T_2}{P_2T_1} = \frac{800 \times 76 \times 273}{760 \times 300}\)

= 72.8cm3

422.

Highly polished silvery surfaces are

A.

poor absorbers and poor emitters of radiation

B.

poor absorbers and good emitters of radiation

C.

good absorbers and poor emitters of radiation

D.

good absorbers and good emitters of radiation

Correct answer is B

No explanation has been provided for this answer.

423.
424.

Which of the following types of thermometer is used for the calibration of other thermometers?

A.

liqud-in-glass thermometer

B.

constant volume gas thermometer

C.

optical pyrometer

D.

thermocouple

Correct answer is B

No explanation has been provided for this answer.

425.

The velocity ratio of an inclined plane

A.

increases with increase in the angle of inclination

B.

increases with decrease in the angle of inclination

C.

decreases with decrease in the angle of inclination

D.

is independent of the angle of inclination

Correct answer is A

No explanation has been provided for this answer.