Heat Transfer - Jamb Physics Past Questions and Answers

Question 16:

• 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

Question 17:

• JAMB 1992

The space between the double glass walls of a thermos flask is evacuated space are silvered. The residual source of heat loss takes place by

A. Convection
B. Radiation from the surface
C. Conduction through the stopper and the glass
D. Conduction across the walls

Question 18:

• JAMB 1994

Two similar kettles containing equal masses of boiling water are placed on a table. If the surface of one is highly polished and the surface of the other is covered with soot, Which of the following observations is correct

A. The two kettles will cool down at the same rate
B. The polished kettle cools down more quickly by conduction
C. The kettle covered with soot cools down more quickly because it is a good radiator
D. The kettle covered with soot cools down more quickly by the process of heat convection

Question 19:

• JAMB 2000

The main reason for making the cover of a vacuum flask airtight is to prevent heat loss by

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

Question 20:

• JAMB 2001

Ice cubes are added to a glass of warm water. The glass and water are cooled by

A. Conduction only
B. Convection only
C. Conduction and convection
D. Convection and radiation