Plane Wall - Steady-State Heat Conduction - MCQs with Answers
Q1. What is the correct formula for the rate of heat transfer (q) through a plane wall of thickness l and surface are A, when temperature difference between two surfaces is ΔT ? The thermal conductivity is k.a.
q = (k A ΔT) / l b.
q = k A l ΔTc.
q = (ΔT) / (k A l)d. none of the above
View Answer / Hide Answer ANSWER: a. q = (k A ΔT) / l
Q2. Thermal conductivity of the same material varies witha. the thickness of the material
b. the temperature of the material
c. both a. and b.
d. thermal conductivity of the same martial does not vary at all
View Answer / Hide Answer ANSWER: b. the temperature of the material
Q3. The surface temperatures of a plate with thickness of 0.06 m are 100°C and 40°C. The thermal conductivity (k) of wall is 350 W/mK. What is the rate of heat transfer through the plate in kW/m2?a. 350000
b. 350
c. 35
d. 0.35
View Answer / Hide Answer Q4. How does the thermal conductivity of a material change with respect to change in temperature of the same material?a. thermal conductivity of a material increases with increase in its temperature
b. thermal conductivity of a material decreases with increase in its temperature
c. thermal conductivity of a material remains same with change in its temperature
d. unpredictable
View Answer / Hide Answer ANSWER: a. thermal conductivity of a material increases with increase in its temperature