# Heat Transfer 2

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Heat Transfer 2

Part 2: List for questions and answers of Heat Transfer

Q1.Thermal conductivity of the same material varies with
a) The thickness of the material
b) The temperature of the material
c) Both a. And b
d) Thermal conductivity of the same martial does not vary at all

Q2.The surface temperatures of a plate with thickness of 0.06 m are 100D deg. C and 40 deg. C. the thermal conductivity (k) of wall is 350 W/mk. What is the rate of heat transfer through the plate in kw/m^2?
a) 350000
b) 350
c) 35
d) 0.35

Q3.How does the thermal conductivity of a material change with respect to change in temperature of the same material?
a) Thermal conductivity of a material increases with increase in its temperature
b) Thermal conductivity of a material decreases with increase in its temperature
c) Thermal conductivity of a material remains same with change in its temperature
d) Unpredictable

Q4.As the radius increases in hollow cylinder the temperature
a) Also increases
b) Decreases
c) It depends upon the direction of heat flow
d) Unpredictable

Q5.What is the effect of change in outer radius of the hollow cylinder on the thermal resistance of conduction?
a) The thermal resistance of conduction increases with increase in outer radius of the hollow cylinder
b) The thermal resistance of conduction decreases with increase in outer radius of the hollow cylinder
c) The thermal resistance of conduction remains same with change in outer radius of the hollow cylinder
d) Unpredictable

Q6.What is the advantage of using the spherical vessel to store fluids at low temperature?
a) Heat transfer in sphere is restricted in all direction by insulation
b) Sphere has the smallest volume per unit surface area
c) Sphere has the largest volume per unit surface area
d) None of the above

Q7.Generally the external thermal resistance between the surface of the body and the environment is
a) Less than the internal conduction resistance in the body
b) More than the internal conduction resistance in the body
c) Same as the internal conduction resistance in the body
d) None of the above

Q8.What is the correct formula for The Biot number?
a) Hl/k
b) K/hl
c) L/hk
d) Hk/l

Q9.Suppose that a hot metal ball is immersed in cold water, then temperature distribution in the body depends upon
a) Thermal conductivity of the body
b) Convective heat transfer from the body surface to water
c) Both a. And b
d) None of the above

Q10.What is lumped heat capacity analysis?
a) The analysis of a system in which it is assumed to be at nonuniform temperature
b) The analysis of a system in which it is assumed to be at uniform temperature
c) The analysis of a system in which it is assumed to be at either uniform or nonuniform temperature
d) None of the above

Q11.The Biot number or Biot modulus is given by
a) The ratio of external convection resistance to the internal conduction resistance
b) The ratio of internal conduction resistance to the external convection resistance
c) Multiplying internal conduction resistance and external convection resistance
d) None of the above

Q12.What should be the Biot number to assume the body at uniform temperature?
a) The Biot number should be less than 0.1
b) The Biot number should be more than 0.1
c) The Biot number should be equal to 0.1
d) None of the above

Q13.The cooling of a metal ball of volume V, in large quantity of fluid is analogous to
a) Discharging of battery in an electric system
b) Discharging of capacitor in an electric system
c) Generation of heat in resistor in an electrical system
d) None of the above

Q14.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

Q15.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

Q16.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

Q17.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
d) None of the above

Q18.The thermocouple circuit which is used to measure temperature works on…
a) Seebeck effect
b) Peltier effect
c) Thomson effect
d) None of the above

Q19.Which of the following is chosen as a standard thermometric substance?
a) Gas
b) Thermocouple
c) Electric resistance
d) Mercury

Q20.Which law of thermodynamics is the basis of temperature measurement?
a) Zeroth law of thermodynamics
b) First law of thermodynamics
c) Second law of thermodynamics
d) None of the above

Part 2: List for questions and answers of Heat Transfer