Heat Transfer Operations Questions and Answers – Condensers Recap

This set of Heat Transfer Operations Multiple Choice Questions & Answers (MCQs) focuses on “Condensers Recap”.

1. What is the expression for heat transfer coefficient for a vertically placed condenser?
a) h_VER=0.943([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
b) h_VER=0.743([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
c) h_VER=0.723([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )} ]^{0.25})
d) h_VER=0.725([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L ) }]^{0.25})

2. What is the expression for heat transfer coefficient for a horizontally placed condenser?
a) h_HOR=0.943([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
b) h_HOR=0.743([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
c) h_HOR=0.723([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
d) h_HOR=0.725([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})

3. As thermal conductivity kF increases, the heat transfer coefficient ________
a) Increases
b) Decreases
c) Remains same
d) Jumps to a high value

4. If there is a decrease in viscosity, the heat transfer coefficient ____________
a) Increase
b) Decrease
c) Remains same
d) Becomes zero

5. A high value of latent heat h_fg means that the heat transfer coefficient would __________
a) Increase
b) Decrease
c) Remains same
d) Becomes zero

6. An increase in diameter means a _________ heat transfer coefficient.
a) Larger
b) Smaller
c) Zero
d) Infinite

7. A large value of temperature difference will lead to more condensation and hence a __________ heat transfer coefficient
a) Larger
b) Smaller
c) Zero
d) Infinite

8. An increase in number of tubes will lead to larger condensate thickness in the lower tubes leading to ____________ heat transfer coefficient
a) Larger
b) Smaller
c) Zero
d) Infinite

9. If the condensation occurs at the outside surface of the tubes, then the equation for the heat transfer coefficient does not change.
a) True
b) False

10. If the condensation occurs at the outside surface of the tubes, then the equation for the heat transfer coefficient cab be represented as which one of the following?
a) h_VER=0.943([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )}]^{0.25})
b) h_VER=1.13([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )} ]^{0.25})
c) h_VER=0.723([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L )} ]^{0.25})
d) h_VER=0.725([frac{K^3 p^2 g h_{fg}}{μx(T_{sat}- T_L ) }]^{0.25})