# Laws of Heat Transfer - Conduction - MCQs with Answers

## Laws of Heat Transfer – Conduction - MCQs with Answers

Q1. According to the Fourier's law of heat conduction, the rate of heat transfer by conduction depends upon

a. area of cross section normal to the heat flow
c. both a. and b.
d. none of the above

ANSWER: c. both a. and b.

Q2. What is the temperature gradient in the conduction heat transfer?

a. change in temperature per unit change in time
b. change in temperature per unit change in distance in the direction of heat flow
c. change in temperature per unit change in cross-sectional area normal to the direction of heat flow
d. change in temperature per unit change in cross-sectional area parallel to the direction of heat flow

ANSWER: b. change in temperature per unit change in distance in the direction of heat flow

Q3. Why is the negative sign introduced in the equation of Fourier's law of heat conduction?

q = – kA (dT / dx)

a. because heat transfer rate is inversely proportional to temperature gradient
b. because value of thermal conductivity k is negative
c. because heat is transferred from higher temperature to lower temperature
d. none of the above

ANSWER: c. because heat is transferred from higher temperature to lower temperature

Q4. The value of thermal conductivity k depends upon

a. the material through which the heat is transferred
b. the intensity of heat energy which is being transferred
c. the area which is parallel to the heat transfer
d. all of the above

ANSWER: a. the material through which the heat is transferred

Q5. The materials which have low thermal conductivity are called as

a. thermal conductors
b. thermal resistors
c. thermal insulators
d. none of the above