Heat Transfer MCQs

Heat transfer co-efficient (h1) for liquids increases with

Baffle spacing

In case of __________ boiling, the bubbles formed on a submerged hot surface get absorbed in the mass of the liquid.

The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium. This is __________ law.

Solid angle subtended by the finite surface at the radiating element is

Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called

Agitated film evaporator is suitable for concentrating __________ liquids.

Which of the following is not concerned with the heat transfer?

1000 Kg of liquid at 30°C in a well stirred vessel has to be heated to 120°C, using immersed coils carrying condensing steam at 150°C. The area of the steam coils is 1.2 m2 and the overall heat transfer co-efficient to the liquid is 1500 W/m2.°C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.°C, the time taken for the liquid to reach desired temperature will be