Question 1

A block of wood and a block of metal feel equally cold or equally hot when touched. Then their common temperature is

Accepted Answer

A) 0°K 
B) 0°F 
C) 0°C 
D) 37,500 kg 
E) the same as that of the human body 
A) 0°K 
B) 0°F 
C) 0°C 
D) 37,500 kg 
E) the same as that of the human body E

Question 2

The expression (A2-A1)/loge (A2/A1) for a hollow cylinder is known as

Accepted Answer

A) Logarithmic mean radius 
B) Mean area of heat transfer 
C) The rate of heat transfer 
D) None of the above 
E) Nichrome 
A) Logarithmic mean radius 
B) Mean area of heat transfer 
C) The rate of heat transfer 
D) None of the above 
E) Nichrome B

Question 3

The numerical value of which property of air generally drops with rising temperature

Accepted Answer

A) Thermal diffusivity 
B) Density 
C) Kinematic viscosity 
D) Thermal conductivity 
E) Dynamic viscosity 
A) Thermal diffusivity 
B) Density 
C) Kinematic viscosity 
D) Thermal conductivity 
E) Dynamic viscosity B

Question 4

In the temperature of air above a pond is 8°C thermal conductivity of ice is 0.005 C.G.S. units, latent heat of fusion of ice is 79.9 cal/gram the density of ice is 1 gm/cu.m, the time taken for the formation of ice layer of 1 cm thickness is

Accepted Answer

A) 200 seconds 
B) 100 seconds 
C) 12.5 seconds 
D) 10 seconds 
E) None of the above 
A) 200 seconds 
B) 100 seconds 
C) 12.5 seconds 
D) 10 seconds 
E) None of the above

Question 5

The diathermous body is one that

Accepted Answer

A) diffuses all the thermal rays in the different directions 
B) allows all the incident radiation to pass through it 
C) 37,500 kg 
D) negligible absorptivity but high reflectivity 
E) absorbs all the thermal rays 
A) diffuses all the thermal rays in the different directions 
B) allows all the incident radiation to pass through it 
C) 37,500 kg 
D) negligible absorptivity but high reflectivity 
E) absorbs all the thermal rays

Question 6

Heat is transferred by conduction, convection and radiation in

Accepted Answer

A) Melting of ice 
B) Refrigerator freezer coils 
C) Boiler furnaces 
D) Condensation of steam in a condenser 
E) Insulated pipes carrying hot water 
A) Melting of ice 
B) Refrigerator freezer coils 
C) Boiler furnaces 
D) Condensation of steam in a condenser 
E) Insulated pipes carrying hot water

Question 7

A slab of ice has one-half covered with black cloth and the other half with white cloth. The slab is now placed in sunlight. It will be observed that

Accepted Answer

A) 37,500 kg 
B) more ice will melt under black cloth 
C) more ice will melt under white cloth 
D) ice will not melt 
E) equal amount of ice will melt under the two cloths 
A) 37,500 kg 
B) more ice will melt under black cloth 
C) more ice will melt under white cloth 
D) ice will not melt 
E) equal amount of ice will melt under the two cloths

Question 8

Thermal conductivity of water at 20°C is nearly

Accepted Answer

A) 0.051 
B) 1 
C) 0.11 
D) 0.09 
E) 0.5 
A) 0.051 
B) 1 
C) 0.11 
D) 0.09 
E) 0.5

Question 9

For temperature below -40°C which one of the following substance can be used as thermometric substance

Accepted Answer

A) Alcohol 
B) Pentane 
C) Ether 
D) Any of the above 
E) None of the above 
A) Alcohol 
B) Pentane 
C) Ether 
D) Any of the above 
E) None of the above

Question 10

Which of the following material has highest value of thermal diffusivity?

Accepted Answer

A) Steel 
B) Concrete 
C) Lead 
D) Mineral wool 
E) Wood 
A) Steel 
B) Concrete 
C) Lead 
D) Mineral wool 
E) Wood

Question 11

The quantity of heat required to change the temperature of 1 gm of ice from -6°C to -5°C is known as

Accepted Answer

A) Freezing heat 
B) Cold heat 
C) Latent heat of freezing 
D) Specific heat 
E) Heat of vaporization 
A) Freezing heat 
B) Cold heat 
C) Latent heat of freezing 
D) Specific heat 
E) Heat of vaporization

Question 12

A black body absorbs all radiations. As a result of absorption of these radiations

Accepted Answer

A) A black body shines 
B) The temperature of black body rises 
C) Black body radiates energy to other bodies 
D) Black body becomes good conductor of heat 
E) None of the above 
A) A black body shines 
B) The temperature of black body rises 
C) Black body radiates energy to other bodies 
D) Black body becomes good conductor of heat 
E) None of the above

Question 13

The value of the wavelength for maximum emissive power is given by

Accepted Answer

A) Stefan law 
B) Wein's law 
C) Planck's law 
D) Kirchhoff's law 
E) D'Alembert's rule 
A) Stefan law 
B) Wein's law 
C) Planck's law 
D) Kirchhoff's law 
E) D'Alembert's rule

Question 14

A non-dimensional number generally associated with natural convection heat transfer is

Accepted Answer

A) Prandtl number 
B) Weber number 
C) Peclet number 
D) Nusselt number 
E) Grashof number 
A) Prandtl number 
B) Weber number 
C) Peclet number 
D) Nusselt number 
E) Grashof number

Question 15

The material preferred for the fabrication of fruit juice concentrator is

Accepted Answer

A) Mild steel sheet 
B) Brass 
C) Cast iron 
D) Stainless steel sheet 
E) Copper 
A) Mild steel sheet 
B) Brass 
C) Cast iron 
D) Stainless steel sheet 
E) Copper

Question 16

Gases have poor

Accepted Answer

A) Absorptivity 
B) Transmissivity 
C) Reflectivity 
D) Reflectivity + absorptivity 
E) Absorptivity + transmissivity 
A) Absorptivity 
B) Transmissivity 
C) Reflectivity 
D) Reflectivity + absorptivity 
E) Absorptivity + transmissivity

Question 17

The unit of thermal diffusivity is

Accepted Answer

A) m2/hr°C 
B) m2/hr 
C) m/hr°C 
D) kcal/m2-hr 
E) m/hr 
A) m2/hr°C 
B) m2/hr 
C) m/hr°C 
D) kcal/m2-hr 
E) m/hr

Question 18

A body which transmits all the radiations falling on it is known as

Accepted Answer

A) Black body 
B) Grey body 
C) Transparent body 
D) White body 
E) None of the above 
A) Black body 
B) Grey body 
C) Transparent body 
D) White body 
E) None of the above

Question 19

The process of removal of oil from oil cakes is known as

Accepted Answer

A) Leaching 
B) Decoction 
C) Osmosis 
D) Soret effect 
E) None of the above 
A) Leaching 
B) Decoction 
C) Osmosis 
D) Soret effect 
E) None of the above

Question 20

Unsteady state of heat flow occurs in

Accepted Answer

A) Flow of heat through furnace walls 
B) Flow of heat through insulated pipe with constant surface temperature 
C) Annealing of castings 
D) Flow of heat through refrigerator walls 
E) None of the above 
A) Flow of heat through furnace walls 
B) Flow of heat through insulated pipe with constant surface temperature 
C) Annealing of castings 
D) Flow of heat through refrigerator walls 
E) None of the above

Exam 10: Heat Transfer and Thermal Properties: Part B

A block of wood and a block of metal feel equally cold or equally hot when touched. Then their common temperature is

The expression (A2-A1)/loge (A2/A1) for a hollow cylinder is known as

The numerical value of which property of air generally drops with rising temperature

In the temperature of air above a pond is 8°C thermal conductivity of ice is 0.005 C.G.S. units, latent heat of fusion of ice is 79.9 cal/gram the density of ice is 1 gm/cu.m, the time taken for the formation of ice layer of 1 cm thickness is

The diathermous body is one that

Heat is transferred by conduction, convection and radiation in

A slab of ice has one-half covered with black cloth and the other half with white cloth. The slab is now placed in sunlight. It will be observed that

Thermal conductivity of water at 20°C is nearly

For temperature below -40°C which one of the following substance can be used as thermometric substance

Which of the following material has highest value of thermal diffusivity?

The quantity of heat required to change the temperature of 1 gm of ice from -6°C to -5°C is known as

A black body absorbs all radiations. As a result of absorption of these radiations

The value of the wavelength for maximum emissive power is given by

A non-dimensional number generally associated with natural convection heat transfer is

The material preferred for the fabrication of fruit juice concentrator is

Gases have poor

The unit of thermal diffusivity is

A body which transmits all the radiations falling on it is known as

The process of removal of oil from oil cakes is known as

Unsteady state of heat flow occurs in

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 A

Heat Transfer and Heat Exchangers: Part B

Heat Transfer and Crystallisation

Heat Transfer and Thermal Properties: Part A

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

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