Jamb Physics 1991 Past Questions and Answers

Question 16:

• JAMB 1991

What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100^oC to 80^oC? [the specific latent heat of steam is 2,260,000Jkg^-1, specific heat capacity of water is 4200Jkg^-1K^-1]

A. 4200J
B. 2,260,OOOJ
C. 9,040,000J
D. 9,380,000J

Question 17:

• JAMB 1991

How long does it take a 750W heater to raise the temperature of 1kg of water from 20^oC to 50^oC [specific heat capacity of water = 4200Jkg^-1K^-1]

A. 84s
B. 112s
C. 168s
D. 280s

Question 18:

• 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 19:

• JAMB 1991

The absolute temperature of a perfect gas is proportional to the average

A. Potential energy of the molecules
B. Seperation between the molecules
C. Kinetic energy of the molecules
D. Velocity of the molecules

Question 20:

• JAMB 1991

A room is heated by means of a charcoal fire, An occupant of the room standing away from the fire is warmed mainly by

A. Convection
B. Radiation
C. Conduction
D. Reflection