The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the___________________?

A. Heating volume
B. Heat transfer area
C. Nusselt number
D. None of these

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are_______________?

A. Re.Gz
B. Nu, Pr
C. Nu, Pr, Re
D. Nu, Gz

Controlling heat transfer film co-efficient is the one, which offers ______________ resistance to heat transfer?

A. No
B. The least
C. The largest
D. Lower

Which one gives the monochromatic emissive power for black body radiation ?

A. Planck’s law
B. Kirchhoff’s law
C. Wien’s law
D. Stefan-Boltzmann law

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

A. Increased economy
B. Decreased economy
C. Lower capacity
D. No effect on economy

The range of electromagnetic spectrum important in heat transfer by radiation is ______________ microns?

A. 0.38-0.78
B. 0.5-50
C. 100-1000
D. 5-50

In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient______________?

A. Increases
B. Decreases
C. Is not affected
D. May increase or decrease; depends on the feed

The advantage of using a 1 – 2 shell and tube heat exchanger over a 1 – 1 shell and tube heat exchanger is_________________?

A. Lower tube side pressure drop
B. Lower shell side pressure drop
C. Higher tube side heat transfer co-efficient
D. Higher shell side heat transfer co-efficient

The energy radiated from a surface Q at absolute temperature T is related as__________________?

A. Q ∝ T2
B. Q ∝ T4
C. Q ∝ T3
D. None of these

With increase in temperature, the thermal conductivity of fresh lubricating oil ___________________?

A. Increases
B. Decreases
C. Remains unchanged
D. May increase or decrease; depends on its composition