Heat Transfer MCQs

A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of materialA is twice that of B. Under the equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A is __________ °C.

It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is

In a forward feed multiple effect, the pressure build up will be

In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will

With increase in temperature, the thermal conductivity of a gas

With increase in temperature, the thermal conductivity of steel

A diathermaneous substance __________ the thermal radiation completely.

For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in

The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is