Boiling Heat Transfer - MCQs with Answers

Boiling Heat Transfer – MCQs with Answers

1. Which of the following is/are example/s of pool boiling?

a. completely submerged electrically heated coil in pool of liquid
b. boiling of liquid in a kettle placed on stove
c. both a. and b.
d. none of the above

View Answer / Hide Answer

2. In pool boiling, as soon as the temperature of heating surface reaches the boiling point of the liquid, heat transfer takes place

a. by conduction
b. by natural convection
c. by forced convection
d. cannot say

View Answer / Hide Answer

3. In pool boiling process, the region after the natural convection in which the vapour bubbles form with increase in heat flux, is called as

a. impure boiling regime
b. pure boiling regime
c. nucleate boiling regime
d. non-nucleate boiling regime

View Answer / Hide Answer

4. When the formation of bubbles becomes very high in pool boiling, then the heat flux

a. rises
b. reduces
c. remains constant
d. becomes unpredictable

View Answer / Hide Answer

5. What is critical heat flux in boiling heat transfer process?

a. the heat flux which reaches at a certain constant value at a particular excess temperature
b. the heat flux which reaches at the minimum value at a particular excess temperature
c. the heat flux which reaches at the maximum value at a particular excess temperature
d. none of the above

View Answer / Hide Answer

6. How does heat flux change with increasing excess temperature in transition boiling regime of boiling heat transfer process?

a. heat flux increases with increasing excess temperature
b. heat flux decreases with increasing excess temperature
c. heat flux becomes constant with increasing excess temperature
d. none of the above

View Answer / Hide Answer

7. Which regime in boiling heat transfer process can represent a transition from nucleate boiling to film boiling?

a. pure convection regime
b. nucleate boiling regime
c. transition boiling regime
d. stable film boiling regime

View Answer / Hide Answer

8. The nuclei of bubbles form in nucleate boiling, when there is presence of

a. superheated vapour
b. superheated liquid
c. dissolved gases
d. undissolved gases

View Answer / Hide Answer

9. When is the condensate flow almost always laminar?

a. when condensation occurs on a horizontal tube
b. when condensation occurs on a vertical bank of horizontal tubes
c. when condensation occurs on a vertical tube
d. when condensation occurs on a bunch of vertical tubes

View Answer / Hide Answer

10. In forced convection boiling process, a liquid flows through a tube with

a. superheated or unsaturated boiling
b. subcooled or saturated boiling
c. subcooled to superheated boiling
d. vapour in boiling

View Answer / Hide Answer