WAEC Physics Past Questions & Answers - Page 180

896.

A wave of weight length 0.30m travels 900m in 3.0s, calculate its frequency

A.

68.0Hz

B.

225.0Hz

C.

1000Hz

D.

750.0Hz

Correct answer is C

V = \(\frac{s}{t} = \frac{900}{3} = 300\)m\s

f = \(\frac{v}{\pi} = \frac{300}{0.30}\)

= 1000Hz

897.

The volume of a given mass of an ideal gas at 327k and 9.52 x 104 Pa is 40cm3. calculate the volume of the gas at 273k and 1.034 x 105Pa.

A.

68.23cm3

B.

47.91cm3

C.

44.60cm3

D.

30.75cm3

Correct answer is D

\(V_2 = \frac{P_1V_1T_2}{P_2T_1} = \frac{9.52 \times 10^4 \times 40 \times 273}{1.034 \times 10^5 \times 327}\)

= 30.75cm3

898.

When the pressure of a fixed mass of gas is doubled at constant temperature, the volume of the gas is

A.

increased four times

B.

doubled

C.

unchangeable

D.

halved

Correct answer is D

No explanation has been provided for this answer.

899.

Which of the following statement about latent heat of vaporization is correct? It

A.

weakens the adhesive force between molecules of a liquid and those of its container

B.

breaks completely the force of attraction completely between the molecules of a liquid

C.

add to the heat content of a liquid

D.

increases the cohesive forces between liquid molecules

Correct answer is B

No explanation has been provided for this answer.

900.

The heat capacity of a calorimeter is the amount of energy required to

A.

change the temperature of 1kg of the calorimeter by 1k

B.

change 1kg mass of the calorimeter to liquid at the same temperature

C.

change the temperature of the calorimeter

D.

melt the calorimeter into liquid at a constant temperature

Correct answer is C

No explanation has been provided for this answer.