Question 11 : Pick out the correct statement.
1. In unsteady state heat conduction, heat flows in the direction of temperature rise.
2. In heat transfer by forced convection, Grashoff number is very important.
3. 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F.
4. In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity.
View Answer   Discuss with Members

Question 12 : jH factor for heat transfer depends upon the __________ number.
1. Biot
2. Prandtl
3. Reynolds
4. Nusselt
View Answer   Discuss with Members

Question 13 : Kg of liquid evaporated per hour in an evaporator is defined as its
1. steam load
2. capacity
3. economy
4. none of these
View Answer   Discuss with Members

Question 14 : Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law.
1. Wien's
2. Stefan's
3. Dalton's
4. Kirchoffs
View Answer   Discuss with Members

Question 15 : Which of the following parameters of the fluid is not very important, while deciding its route in a shell and tube heat exchanger?
1. viscosity
2. pressure
3. density
4. Corrosiveness & fouling characteristics
View Answer   Discuss with Members

Question 16 : Three material A, B and C of equal thick-nes and of thermal conductivity of 20, 40 & 60 kcal/hr. m. °C respectively are joined together. The temperature outside of A and C are 30°C and 100°C respectively. The interface between B and C will be at a temperature of __________ °C.
1. 40
2. 80
3. 70
4. 90
View Answer   Discuss with Members

Question 17 : In a shell and tube heat exchanger, floating head is used for
1. high heat transfer co-efficient.
2. large temperature differentials.
3. low pressure drop.
4. less corrosion of tubes.
View Answer   Discuss with Members

Question 18 : Maximum heat transfer rate is achieved in __________ flow.
1. co-current
2. turbulent
3. counter-current
4. laminar
View Answer   Discuss with Members

Question 19 : A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires
1. more space.
2. less heating surface.
3. lower maintenance cost.
4. none of these
View Answer   Discuss with Members

Question 20 : Heat sensitive materials can be concentrated in an evaporator employing
1. high residence time
2. vacuum
3. none of these
4. high pressure
View Answer   Discuss with Members