Jamb Physics 1987 Past Questions and Answers

Question 16:

• JAMB 1987

Hot water is added to three times its mass of water at 10^oC and the resultant temperature is 20^oC. What is the initial temperature of the hot water?

A. 100^oC
B. 80^oC
C. 50^oC
D. 40^oC

Question 17:

• JAMB 1987

22,000J of heat is required to raise the temperature of 1.5kg of paraffin from 20^oC to 30^oC. Calculate the specific heat capacity of paraffin.

A. 1466Jkg^-1oC^-1
B. 2933Jkg^-1oC^-1
C. 4400Jkg^-1oC^-1
D. 5866Jkg^-1oC^-1

Question 18:

• JAMB 1987

In which of the following are the substance arranged in descending order of their thermal conductivities?

A. Copper, steel, glass
B. Steel, copper, glass
C. Steel, glass, copper
D. Copper, glass, steel

Question 19:

• JAMB 1987

The vacuum in a thermos flask helps to reduce heat transfer by?

A. Convection and radiation
B. Convection and conduction
C. Conduction and radiation
D. Radiation only

Question 20:

• JAMB 1987

Which of the following phenomena explains the fact that a house whose roof is coated with white paint will be cooler in the hot season than one coated with black paint ?

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