

MCQOPTIONS
Saved Bookmarks
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which one of the following statement is not correct about nucleate boiling? |
A. | The temperature of the surface is greater than the saturation temperature of the liquid |
B. | The heat flux is greater than film boiling |
C. | The temperature is greater than film boiling |
D. | Bubbles are created by the expansion of entrapped vapour in the heating surface |
Answer» D. Bubbles are created by the expansion of entrapped vapour in the heating surface | |
2. |
The temperature of operation of nucleate boiling is ___________ film boiling. |
A. | More than |
B. | Less than |
C. | Equal to |
D. | Difficult to be compared than |
Answer» C. Equal to | |
3. |
When the temperature of water is at about 90-100 degrees more than its boiling point, then what is the name of this type of boiling? |
A. | Nucleate |
B. | Stable Film boiling |
C. | Partially stable film boiling |
D. | Radiation boiling |
Answer» D. Radiation boiling | |
4. |
The Leiden Frost effect is observed in _________ of liquids. |
A. | Boiling |
B. | Cooling |
C. | Freezing |
D. | Radiation superheating |
Answer» B. Cooling | |
5. |
The increase in heat flux after the Leiden Frost Point is due to ___________ |
A. | Radiation |
B. | Convection |
C. | Conduction |
D. | Flash |
Answer» B. Convection | |
6. |
Which one of the following correctly represents the axes of the boiling curve? |
A. | Y: Heat flux and X: Temperature |
B. | X: Heat transfer coefficient and Y: Temperature |
C. | X: Heat flux and Y: Temperature |
D. | Y: Heat flux and X: Temperature difference |
Answer» B. X: Heat transfer coefficient and Y: Temperature | |
7. |
With increase in temperature of boiling operation, the heat transfer flux ___________ |
A. | Decreases |
B. | Increases |
C. | Increases at first, then decreases |
D. | Increases at first, then decreases and later again increases |
Answer» E. | |
8. |
The size of the bubble on nucleation _________ as it rises up. |
A. | Increases |
B. | Decreases |
C. | Remains same |
D. | Breaks to many bubbles |
Answer» B. Decreases | |
9. |
The height of the superheated layer in nucleate boiling is __________ the diameter of the departing bubble. |
A. | Greater than |
B. | Less than |
C. | Equal to |
D. | Much greater than |
Answer» C. Equal to | |
10. |
What is the significance of the term “ σ ” in the given Fritz Equation used to calculate bubble departure diameter?D = Cd β [2 σ/g (PL – PV )]½ |
A. | Surface Tension |
B. | Contact Angle |
C. | Liquid density |
D. | Gas density |
Answer» B. Contact Angle | |
11. |
Which one of the following is the correct representation of Fritz equation which is used to calculate bubble diameter in bubble pool boiling? |
A. | D = Cd β [2 σ/g (pt – pv)]½ |
B. | D = Cd β [σ/g (pt – pv)]½ |
C. | D = Cd β [2 σ/g (pt – pv)]2 |
D. | D = Cd β [2 σ/g (pt – pv)] |
Answer» B. D = Cd β [σ/g (pt – pv)]½ | |
12. |
The Fritz equation to calculate the bubble diameter is given by –D = Cd β [2 σ/g (ϸL – ϸV )]½What is the value of the constant Cd for water bubbles at 1atm? |
A. | 0.0148 |
B. | 0.003 |
C. | 0.0027 |
D. | 0.00148 |
Answer» B. 0.003 | |
13. |
Which one of the following conditions does not influence Nucleate pool boiling? |
A. | Pressure |
B. | Liquid properties |
C. | Heat capacity of fluid |
D. | Material of heating |
Answer» D. Material of heating | |
14. |
The diameter of the bubble that gets detached from the heating surface during boiling can be found by which one of the following relations? |
A. | Stanton’s Relation |
B. | Fritz Relation |
C. | Fourier Theory |
D. | Nusselt’s Theory |
Answer» C. Fourier Theory | |