Top 50+ Solved Heat Transfer MCQ Questions Answer
Q. 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 gradient of the body
c. dependent upon the material of the body
d. all of the above.
Q. Which of the following is expected to have highest thermal conductivity
a. steam
b. solid ice
c. melting ice
d. water
Q. Thermal conductivity of a material may be defined as the
a. quantity of heat flowing in one second through one cm cube of material when opposite faces are maintained at a temperature difference of 1°C
b. quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C
c. heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces
d. all of the above
Q. Which of the following has maximum value of thermal conductivity
a. aluminium
b. steel
c. brass
d. copper
Q. Heat is transferred by all three modes of transfer (conduction, convection and radiation) in,
a. electric heater
b. steam condenser
c. melting of ice
d. boiler.
Q. 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
Q. Thermal conductivity of wood depends on
a. moisture
b. density
c. temperature
d. all of the above
Q. Heat conducted through unit area and unit thick face per unit time when temperature difference between opposite facesis unity,is called
a. thermal resistance
b. thermal coefficient
c. temperature gradient
d. thermal conductivity
Q. 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
Q. A grey body is one whose absorptivity
a. varies with temperature
b. varies with wavelength of the incident ray
c. is equal to its emissivity
d. does not vary with temperature and wavelength of the incident ray
Q. A non-dimensional number generally associated with natural convection heat transfer is
a. Grashoff number
b. Nusselt number
c. Weber number
d. Prandtl number
Q. LMTD in case of counter flow heat exchanger as compared-to parallel flow heat exchanger is
a. higher
b. lower
c. same
d. depends on the area of heat exchanger
Q. In counter flow heat exchangers
a. both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state
b. both the fluids at inlet are in their hottest state
c. both the fluids .at exit are in their hottest state
d. one fluid is in hottest state and other in coldest state at inlet
Q. Fourier's law of heat conduction is valid for
a. one dimensional cases only
b. two dimensional cases only
c. three dimensional cases only
d. regular surfaces having non-uniform temperature gradients