Heat and Mass Transfer MCQs

A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is

If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ and λ + dλ is represented by (eλ.dλ), then eλ is called

The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles due to difference of density caused by temperature of the particle is known as

The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called

Fourier's law of heat conduction is valid for

According to Newton's law of cooling, the heat transfer from a hot body to a cold body is

Absorptivity of a body will be equal to its emissivity

In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in

A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer,