Heat Transfer MCQs

Electro-magnetic spectrum range, which is important for radiation varies from __________ microns.

Which of the following has the lowest Prandtl number?

Which has the lowest Prandtl number?

The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation.

For a given ambient air temperature with increase in the thickness of insulation of a hot cylinderical pipe, the rate of heat loss from the surface would

The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are

Overall thermal resistance for conductive heat transfer through a series of flat resistances is equal to the

In a shell and tube heat exchanger, the tube side heat transfer co-efficient just at the entrance of the tube is

Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer can not take place