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Free download in PDF Heat Transfer Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for competitive exams like IIT-JEE, AIIMS, NEET etc. as well as Board exams. These short solved questions or quizzes are provided by Gkseries.
(1)
Unit of thermal conductivity in M.K.S. units is
[A]
kcal/kg m2 °C
[B]
kcal-m/hr m2 °C
[C]
kcal/hr m2 °C
[D]
kcal-m/hr °C
(2)
Thermal conductivity of solid metals with rise in temperature normally
[A]
Increases
[B]
Decreases
[C]
Remains Constant
[D]
May Increase Or Decrease Depending On Temperature
(3)
When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by
[A]
Conduction
[B]
Convection
[C]
Radiation
[D]
Conduction And Convection
(4)
When heat is Transferred by molecular collision, it is referred to as heat transfer by
[A]
Conduction
[B]
Convection
[C]
Radiation
[D]
Scattering
(5)
Pick up the wrong case. Heat flowing from one side to other depends directly on
[A]
Face Area
[B]
Time
[C]
Thickness
[D]
Temperature Difference
(6)
Which of the following is a case of steady state heat transfer
[A]
I.C. Engine
[B]
Air Preheaters
[C]
Heating Of Building In Winter
[D]
None Of The Above
Answer: Ciliated Epithelium
(7)
Cork is a good insulator because it has
[A]
Free Electrons
[B]
Atoms Colliding Frequency
[C]
Low Density
[D]
Porous Body
(8)
Thermal conductivity of water at 20°C is of the order of
[A]
0.1
[B]
0.23
[C]
0.42
[D]
0.51
(9)
Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of
[A]
0.002
[B]
0.02
[C]
0.01
[D]
0.1
(10)
Heat flows from one body to other when they have
[A]
Different Heat Contents
[B]
Different Specific Heat
[C]
Different Atomic Structure
[D]
Different Temperatures
Answer: Different Temperatures
(11)
The amount of heat flow through a body by conduction is
[A]
directly proportional to the surface area of the body
[B]
directly proportional to the temperature difference on the two faces of the body
[C]
dependent upon the material of the body
[D]
all of the above
(12)
Which of the following has least value of conductivity
[A]
Glass
[B]
Water
[C]
Plastic
[D]
Air
(13)
Which of the following is expected to have highest thermal conductivity
[A]
Steam
[B]
Solid Ice
[C]
Melting Ice
[D]
Water
(14)
Which of the following has maximum value of thermal conductivity
[A]
Aluminium
[B]
Steel
[C]
Brass
[D]
Copper
(15)
Heat is transferred by all three modes of transfer, viz, conduction, convection and radiation in
[A]
Electric Heater
[B]
Steam Condenser
[C]
Melting Of Ice
[D]
Boiler
(16)
Heat transfer by radiation mainly depends upon
[A]
Its Temperature
[B]
Nature Of The Body
[C]
Kind And Extent Of Its Surface
[D]
All Of The Above
(17)
Unit of thermal diffusivity is
[A]
m2/hr
[B]
m2/hr°C
[C]
kcal/m2 hr
[D]
kcal/m.hr°C
(18)
Film coefficient is defined as Inside diameter of tube
[A]
Equivalent thickness of film
[B]
Thermal conductivity Equivalent thickness of film Specific heat x Viscocity
[C]
Film coefficient x Inside diameter Thermalconductivity
[D]
none of the above
Answer: Thermal conductivity Equivalent thickness of film Specific heat x Viscocity
(19)
The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as
[A]
Emissivity
[B]
Transmissivity
[C]
Reflectivity
[D]
Intensity Of Radiation
Answer: Intensity Of Radiation
(20)
Emissivity of a white polished body in comparison to a black body is
[A]
higher
[B]
Lower
[C]
Same
[D]
Depends Upon The Shape Of Body