Heat Transfer - Jamb Physics Past Questions and Answers

Question 31:

• JAMB 2012

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 32:

• JAMB 2012

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

Question 33:

• JAMB 2013

Food cook quicker in salt water than in pure water because of the effect of

A. Dissolved substances on the boiling point
B. Atmospheric pressure on the boiling point
C. Food nutrients on the thermal energy
D. Salts on the thermal conductivity of water

Question 34:

• JAMB 2013

The mechanism of heat transfer from one point to another through the vibration of the molecules of the medium is

A. Covection
B. Conduction
C. Radiation
D. Diffusion

Question 35:

• JAMB 2014

Heat transfer by convection in a liquid is due to the

A. Latent heat of vaporization of the liquid
B. Increased vibration of the molecules of the liquid about theit mean position
C. Variation of density of the liquid
D. Expansion of the liquid as it is heated