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1) Heat transfer deals with the rate of a. work transfer b. temperature transfer c. energy transfer d. none of the above
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2) Which among the following has lowest thermal conductivity among the others? a. silver b. water c. mercury d. copper
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3) In gases, the transfer of heat takes place by a. volumetric density b. transporting energy with free electrons c. unstable elastic collision d. random molecular collision
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4) How does the heat transfer take place in metals? a. volumetric density b. transporting energy with free electrons c. unstable elastic collision d. random molecular collision d. None of the above
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5) Internal energy of a substance is associated with a. microscopic modes of energy b. macroscopic modes of energy c. both a. and b. d. none of the above
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6) In which phase of a substance does conduction mode of heat transfer take place? a. solid b. liquid c. gaseous d. all of the above
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7) Mass transfer does not take place in a. conduction heat transfer b. convection heat transfer c. radiation heat transfer d. none of the above
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8) What is the condition for conduction mode of heat transfer between two bodies? a. the two bodies must be in physical contact b. there must be temperature gradient between the bodies c. both a. and b. d. none of the above
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9) In which mode, does the heat energy transfer between two bodies when they are separated by some distance and there is no any medium between them? a. conduction mode of heat transfer b. convection mode of heat transfer c. radiation mode of heat transfer d. heat transfer cannot takes place with above condition
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10) The radiant heat emitted by any body travels at the speed a. less than the speed of light b. more than the speed of light c. equals to the speed of light d. unpredictable
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11) In convection heat transfer energy transfer takes place between a. two solid surfaces connected physically b. solid surface and fluid system in motion c. both a. and b. d. none of the above
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12) The convection heat transfer coefficient depends upon a. the thermal properties of fluid b. geometry of the system c. characteristics of the fluid flow d. all of the above
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13) In a process of heat transfer by convection from a body to the surrounding fluid, the convection heat transfer coefficient a. remains constant over the entire surface of the body b. does not remain constant over the entire surface of the body c. Both A & B d. none of the above
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14) Which two processes are unitedly responsible in the transfer of heat between solid surface and surrounding fluid? a. conduction and convection b. conduction and mass transfer c. convection and mass transfer d. none of the above
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15) When the surface of a body is at higher temperature than the surrounding fluid, then the heat flows firstly from surface of the body to the adjacent layer of fluid by a. convection b. conduction c. radiation d. none of the above
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16) The fluid flow in which the fluid particles in one layer do not mix with the fluid particles in the other layer is called as a. laminar flow b. turbulent flow c. layer flow d. none of the above
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17) Generally, all the fluid particles in flowing fluid a. flow at a constant velocity b. flow at various velocities c. flow at a velocity as high as possible d. none of the above
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18) What is the relation between the rate of convection heat transfer and the rate of mixing in turbulent fluid flow? a. the rate of convection heat transfer decreases with increase in the rate of mixing in turbulent fluid flow b. the rate of convection heat transfer increases with increase in the rate of mixing in turbulent fluid flow c. the rate of convection heat transfer does not affected by the change in the rate of mixing in turbulent fluid flow d. none of the above
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19) Viscosity of a fluid can be defined as a. change in density of the fluid per unit temperature b. flow resistance offered by the fluid c. flow velocity change d. none of the above
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20) The radiation takes place a. through molecular communication b. through vacuum c. both a. and b. d. none of the above
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