Vapours - Jamb Physics Past Questions and Answers

Question 6:

• JAMB 1991

The saturated vapour pressure of a liquid increases as the

A. Volume of the liquid increases
B. Volume of the liquid decreases
C. Temperature of the liquid increases
D. Temperature of the liquid decreases

Question 7:

• JAMB 1994

If a room is saturated with water vapour, the temperature of the room must be

A. At 0^oC
B. Above the dew point
C. At 100^oC
D. Below or at the dew point

Question 8:

• JAMB 1998

A vapour is said to be saturated when

A. More molecules return to the liquid than the amount that left it
B. A dynamic equilibrium exists between the molecules of the liquid and the vapour molecules at a given temperature
C. The vapour pressure is equal to the atmospheric pressure
D. All molecules are moving with the same speed in all directions at a given temperature

Question 9:

• JAMB 2000

Dry
Day 1 - 30°C | Day 2 - 29°C | Day 3 - 25°C
Wet
Day 1 - 22°C | Day 2 - 22°C | Day 3 - 21°C
The reading above are for three consecutive days from a wet and dry bulb hygrometer. It can be concluded that the relative humidity for the three days

A. Decreased steadily
B. Remained unchanged
C. Increased steadily
D. Was least on Day 1

Question 10:

• JAMB 2003

T^oC051015204060S.V.P(mmHg)4.586.518.9412.6717.5055.10149.00
The table above shows the saturation vapour pressure against temperature in a certain town. If the vapour pressure in this town at 20^oC is 10mmHg, what is the relative humidity?

A. 170.0%
B. 57.0%
C. 17.5%
D. 10.0%