SECTION-3

HEAT AND MASS TRANSFER MCQ

##### Q1. The insulation ability of an insulator with the presence of moisture would

(a) increase

(b) decrease

(c) may increase/decrease depending on temperature and thickness of insulation

(d) remain unaffected

Ans: (b) decrease

##### Q2. Which of the following is expected to have highest thermal conductivity

(a) steam

(b) solid ice

(c) melting ice

(d) water

Ans: (b) solid ice

##### Q3. Which of the following has maximum value of thermal conductivity

(a) aluminium

(b) steel

(c) brass

(d) copper

Ans: (a) aluminium

##### Q4. Moisture would find its way into insulation by vapour pressure unless it is prevented by

(a) high thickness of insulation

(b) high vapour pressure

(c) less thermal conductivity insulator

(d) a vapour seal

Ans: (d) a vapour seal

##### Q5. Thermal diffusivity is

(a) a dimensionless parameter

(b) function of temperature

(c) used as mathematical model

(d) a physical property of the material

Ans: (d) a physical property of the material

##### Q6. Sensible heat factor (SHF) is defined as the ratio of

(a) latent heat to sensible heat
(b) sensible heat to latent heat
(c) latent heat to total heat
(d) sensible heat to total heat.

Ans:(d) sensible heat to total heat.

##### Q7. If the critical temperature of a refrigerant is very near the condensing temperature, the power requirements are

(a) small
(b) large
(c) same
(d) none of the above.

Ans:(b) large

##### Q8. The critical temperature of ammonia as compared to that of Freon-22 is

(a) low
(b) high
(c) same
(d) none of the above.

Ans:(b) high

##### Q9. A refrigerant should have the freezing temperature

(a) below –35°C
(b) above –35°C
(c) at –35°C
(d) none of the above.

Ans:(a) below –35°C

##### Q10. The boiling point of Freon-22 is

(a) –40.8°C
(b) –29.8°C
(c) –33.3°C
(d) –78.5°C.

Ans:(a) –40.8°C

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##### Read More Sections of Heat Transfer and Mass Transfer

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Heat and Mass Transfer, RAC  MCQ – Section-1

Heat and Mass Transfer, RAC  MCQ – Section-2

Heat and Mass Transfer, RAC  MCQ – Section-3

Heat and Mass Transfer, RAC  MCQ – Section-4