Question 1

Heat transfer rate per unit area is called

Accepted Answer

A) Thermal conductivity 
B) Heat flux 
C) Heat transfer co-efficient 
D) Thermal diffusivity 
A) Thermal conductivity 
B) Heat flux 
C) Heat transfer co-efficient 
D) Thermal diffusivity B

Question 2

Prandtl number is given by

Accepted Answer

A) CP µ/a 
B) hD/k 
C) CP µ/k 
D) µ/h CP 
A) CP µ/a 
B) hD/k 
C) CP µ/k 
D) µ/h CP C

Question 3

For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone.

Accepted Answer

A) Extremely low 
B) Low 
C) High 
D) No 
A) Extremely low 
B) Low 
C) High 
D) No C

Question 4

Tube pitch is the __________ of tube diameters and the clearances.

Accepted Answer

A) Sum 
B) Difference 
C) Ratio 
D) None of these 
A) Sum 
B) Difference 
C) Ratio 
D) None of these

Question 5

A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material 'A' is

Accepted Answer

A) 125 
B) 133 
C) 150 
D) 160 
A) 125 
B) 133 
C) 150 
D) 160

Question 6

In a multiple effect evaporator, the effect of boiling point elevation is to

Accepted Answer

A) Reduce the capacity 
B) Reduce the economy 
C) Increase the economy 
D) None of these 
A) Reduce the capacity 
B) Reduce the economy 
C) Increase the economy 
D) None of these

Question 7

Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then

Accepted Answer

A) U1 = U2 
B) U2 > U1 
C) U1 > U2 
D) U1 = dirt factor - U2 
A) U1 = U2 
B) U2 > U1 
C) U1 > U2 
D) U1 = dirt factor - U2

Question 8

Heat exchanger tubes are never made of

Accepted Answer

A) Plain carbon steel 
B) Stainless steel 
C) Lead 
D) Copper 
A) Plain carbon steel 
B) Stainless steel 
C) Lead 
D) Copper

Question 9

For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it

Accepted Answer

A) Occupies smaller space 
B) Is more economical 
C) Is easy to operate and maintain 
D) All (
A) , (
B)  and (
C)  
A) Occupies smaller space 
B) Is more economical 
C) Is easy to operate and maintain 
D) All (
A) , (
B)  and (
C)

Question 10

Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law.

Accepted Answer

A) Stefan's 
B) Dalton's 
C) Wien's 
D) Kirchoff's 
A) Stefan's 
B) Dalton's 
C) Wien's 
D) Kirchoff's

Question 11

A black body when hot, emits heat radiation of __________ wavelengths.

Accepted Answer

A) Small 
B) Large 
C) All 
D) One fixed 
A) Small 
B) Large 
C) All 
D) One fixed

Question 12

In case of a vertical tube evaporator, with increase in the liquor level, the __________ is increased.

Accepted Answer

A) Velocity of circulation 
B) Liquor-film co-efficient 
C) Both (
A)  and (
B)  
D) Neither (
A)  and (
B)  
A) Velocity of circulation 
B) Liquor-film co-efficient 
C) Both (
A)  and (
B)  
D) Neither (
A)  and (
B)

Question 13

Steam trap is used to

Accepted Answer

A) Condense the steam flowing in the pipeline 
B) Remove water resulting from partial condensation of steam 
C) Stop the supply of steam 
D) None of these 
A) Condense the steam flowing in the pipeline 
B) Remove water resulting from partial condensation of steam 
C) Stop the supply of steam 
D) None of these

Question 14

The heat flux in the nucleate boiling regimes is proportional to (where, ?T = excess temperature)

Accepted Answer

A) (?T)2 
B) (?T)4 
C) (?T)3 
D) ?(?T) 
A) (?T)2 
B) (?T)4 
C) (?T)3 
D) ?(?T)

Question 15

The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe)

Accepted Answer

A) K/h0 
B) 2K/h0 
C) hi/K 
D) 2hi/K 
A) K/h0 
B) 2K/h0 
C) hi/K 
D) 2hi/K

Question 16

Agitated film evaporator is suitable for concentrating __________ liquids.

Accepted Answer

A) Foaming 
B) Viscous 
C) Very thin 
D) Corrosive 
A) Foaming 
B) Viscous 
C) Very thin 
D) Corrosive

Question 17

Sensible heat of hot industrial flue gases cannot be recovered by a/an

Accepted Answer

A) Economiser 
B) Regenerator 
C) Ceramic recuperator 
D) None of these 
A) Economiser 
B) Regenerator 
C) Ceramic recuperator 
D) None of these

Question 18

In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used

Accepted Answer

A) In low range of temperature differences 
B) In high range of temperature differences 
C) Because of its low cost 
D) To prevent corrosion of the tube bundles 
A) In low range of temperature differences 
B) In high range of temperature differences 
C) Because of its low cost 
D) To prevent corrosion of the tube bundles

Question 19

A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of material A is twice that of B. Under the equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A is __________ °C.

Accepted Answer

A) 6 
B) 12 
C) 18 
D) 24 
A) 6 
B) 12 
C) 18 
D) 24

Question 20

Double pipe heat exchangers are used

Accepted Answer

A) When heat transfer area required is very high 
B) When heat transfer area required is very low, i.e. (100-200 ft2). 
C) Because it occupies less floor area 
D) Because it is less costly 
A) When heat transfer area required is very high 
B) When heat transfer area required is very low, i.e. (100-200 ft2). 
C) Because it occupies less floor area 
D) Because it is less costly

Heat transfer rate per unit area is called

Prandtl number is given by

For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone.

Tube pitch is the __________ of tube diameters and the clearances.

In a multiple effect evaporator, the effect of boiling point elevation is to

Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then

Heat exchanger tubes are never made of

For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it

Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law.

A black body when hot, emits heat radiation of __________ wavelengths.

In case of a vertical tube evaporator, with increase in the liquor level, the __________ is increased.

Steam trap is used to

The heat flux in the nucleate boiling regimes is proportional to (where, ?T = excess temperature)

The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe)

Agitated film evaporator is suitable for concentrating __________ liquids.

Sensible heat of hot industrial flue gases cannot be recovered by a/an

In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used

Double pipe heat exchangers are used

Thermal Conductivity and Heat Transfer

Heat Transfer and Thermal Conductivity: Part A

Heat Transfer and Thermal Conductivity: Part B

Heat Transfer and Thermal Conductivity: Part C

Heat Transfer and Evaporator

Heat Transfer and Heat Exchangers: Part B

Heat Transfer and Crystallisation

Heat Transfer and Thermal Properties: Part A

Heat Transfer and Thermal Properties: Part B

Heat Exchangers and Condensation

Thermal Properties and Processes

Concepts in Heat Transfer

Components of Radiation From Flames

Heat Transfer and Thermodynamics

Heat Transfer Processes, Thermometers, and Evaporators

Heat Transfer and Thermal Properties: Part A

Heat Transfer Mechanisms in a Spaced Plate System

Heat Transfer and Evaporation

Understanding the Dominant Mechanism of Heat Transfer

Heat Transfer and Fluid Mechanics

Heat Transfer and Boiling Point Elevation in Solutions

Filters

Exam 6: Heat Transfer and Heat Exchangers: Part A

Heat transfer rate per unit area is called

Prandtl number is given by

For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone.

Tube pitch is the __________ of tube diameters and the clearances.

In a multiple effect evaporator, the effect of boiling point elevation is to

Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then

Heat exchanger tubes are never made of

For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it

Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law.

A black body when hot, emits heat radiation of __________ wavelengths.

In case of a vertical tube evaporator, with increase in the liquor level, the __________ is increased.

Steam trap is used to

The heat flux in the nucleate boiling regimes is proportional to (where, ?T = excess temperature)

The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe)

Agitated film evaporator is suitable for concentrating __________ liquids.

Sensible heat of hot industrial flue gases cannot be recovered by a/an

In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used

Double pipe heat exchangers are used

Thermal Conductivity and Heat Transfer

Heat Transfer and Thermal Conductivity: Part A

Heat Transfer and Thermal Conductivity: Part B

Heat Transfer and Thermal Conductivity: Part C

Heat Transfer and Evaporator

Heat Transfer and Heat Exchangers: Part B

Heat Transfer and Crystallisation

Heat Transfer and Thermal Properties: Part A

Heat Transfer and Thermal Properties: Part B

Heat Exchangers and Condensation

Thermal Properties and Processes

Concepts in Heat Transfer

Components of Radiation From Flames

Heat Transfer and Thermodynamics

Heat Transfer Processes, Thermometers, and Evaporators

Heat Transfer and Thermal Properties: Part A

Heat Transfer Mechanisms in a Spaced Plate System

Heat Transfer and Evaporation

Understanding the Dominant Mechanism of Heat Transfer

Heat Transfer and Fluid Mechanics

Heat Transfer and Boiling Point Elevation in Solutions

Filters