Heat Transfer
Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is

Uniformly distributed throughout the fluid
In the central core of the fluid
Mainly confined to a thin film of fluid near the surface
None of these

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is

Shell and tube heat exchanger with air on shell side and steam inside tubes
Finned tube heat exchanger with air outside and steam inside
Finned tube heat exchanger with air inside and steam outside
Shell and tube heat exchanger with air inside tubes and steam on shell side

ANSWER DOWNLOAD EXAMIANS APP

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

22 min
44 min
15 min
51 min

ANSWER DOWNLOAD EXAMIANS APP