Heat Transfer Operations Questions and Answers – Condensers Overview

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

1. Which one of the following best describes the function of a condenser?
a) Solid feed to a liquid phase product
b) Vapour feed to a liquid phase product
c) Liquid feed to a solid phase product
d) Liquid feed to a vapour phase product
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2. The convective heat transfer coefficients for condensation in Condensers usually lie in the range ____________
a) 0-200 W/m²K
b) 60-300 W/m²K
c) 300-1000 W/m²K
d) 2500-6000 W/m²K
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3. Which one of the following condensation phenomenon is usually avoided in Condensers?
a) Drop-wise condensation
b) Film condensation
c) Boundary layer condensation
d) Horizontal surface Drop-wise condensation
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4. Which one of the following is not correct about the condensation regimes in a condenser?
a) If a condensing liquid does not wet a surface, then drop wise condensation will not take place on it
b) Drop-wise condensation gives a higher heat transfer rate than film wise condensation
c) Reynolds number of condensing liquid is based on its mass flow rate of the outgoing condensed fluid
d) Suitable coating or vapour additive is used to promote film wise condensation
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5. Which one of the following is the correct classification of condensation process?
a) Batch and Semi-batch condensation
b) Drop-wise and Film-wise condensation
c) Boundary layer and Thermal layer condensation
d) Nucleate and non-nucleate condensation
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6. A plate condenser is usually designed to be kept vertical. How would the condensation coefficient change if due to site constraints it now has to be kept at an angle of 30o to the horizontal?
a) 1.53% reduction in condensation coefficient
b) 50% reduction in condensation coefficient
c) 16% reduction in condensation coefficient
d) 84% reduction in condensation coefficient
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7. If we place a condenser at an angle of α to the vertical, then the convective heat transfer coefficient can be represented as ____________
a) h_INC = 0.943 \(0.943[\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} – T_L)}sin⁡\alpha]^{0.25}\)
b) h_INC = 0.943 \(0.943[\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} – T_L)}tan\alpha]^{0.25}\)
c) h_INC = 0.943 \(0.943[\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} – T_L)}cos⁡\alpha]^{0.25}\)
d) h_INC = 0.943 \(0.943[\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} – T_L)}cosec⁡\alpha]^{0.25}\)
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8. What is the ratio of convective heat transfer coefficients of a inclined condenser to a vertical condenser?
a) \(\frac{h_{INC}}{h_{VER}}\) = cosec⁡α^0.25
b) \(\frac{h_{INC}}{h_{VER}}\) = cos⁡α
c) \(\frac{h_{INC}}{h_{VER}}\) = sin⁡α^0.25
d) \(\frac{h_{INC}}{h_{VER}}\) = tan⁡α^0.25
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9. In a vertical setup of a Condenser, the value of convective heat transfer coefficient depends on the thermal conductivity as ___________
a) k^0.25
b) k^0.33
c) k^0.75
d) k^-0.5
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10. Frictional losses in condensers is usually ____________
a) Very high
b) Very low
c) Low
d) Negligible or 0
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11. For pure vapour as well as mixed liquid, the condensation is isothermal.
a) True
b) False
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12. As the liquid condenses and flows down the condenser wall, the film thickness _________ and the heat transfer coefficient _________
a) Increases, decreases
b) Increases, Increases
c) Decreases, Increases
d) Decreases, decreases
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Sanfoundry Global Education & Learning Series – Heat Transfer Operations.

To practice all areas of Heat Transfer Operations, here is complete set of 1000+ Multiple Choice Questions and Answers.