40 TOP Heat Transfer Online Test – Multiple Choice Questions and Answers

1. Loss of heat from untagged steam pipe to the ambient air is by

2. Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is

3. Tubes are held between top and bottom tube sheets in Calenderia type evaporator by keeping

4. At constant temperature, the thermal conductivities of gases __________ with rise in pressure

5. Low thermal conductivity of heat insulating materials is due to its

6. Small scale evaporation is done in a

7. Value of Nusselt number [Nu = (hD/k)] for the heat transfer by conduction from a droplet or a spherical particle to a surrounding stagnant film is

8. With increase in temperature, the total emissivity of conductors

9. In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of

10. Fruit juice (a heat sensitive material) can be concentrated in a __________ evaporator