Increases the rate of condensation
Decreases thermal resistance
Is desirable to increase the film co-efficient
None of these
✅ The correct answer is option D.
Heat Transfer MCQs
Black liquor generated during paper manufacture is concentrated in a
Single effect evaporator
Single effect evaporator followed by a crystalliser
Multiple effect evaporator
Multiple effect evaporators followed by a crystalliser
✅ The correct answer is option C.
Absorptivity and refletivity of a perfect black body are respectively
1 and 0
0 and 1
1 and ?
0 and 0.5
✅ The correct answer is option A.
Baffles are provided in heat exchangers to increase the
Fouling factor
Heat transfer area
Heat transfer co-efficient
Heat transfer rate
✅ The correct answer is option C.
In a heat exchanger, one transfer unit means
A section of the exchanger in which change in temperature of one stream equals the average driving force in the section
The size of the exchanger in which heat transfer rate is 1 kcal/hr
Both A and B
None of these
✅ The correct answer is option A.
For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in
Increased economy
Decreased economy
Lower capacity
No effect on economy
✅ The correct answer is option A.
Temperature profile in steady state heat transfer is
Asymptotic
Hyperbolic
Parabolic
Linear
✅ The correct answer is option D.
Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity?
Aluminium foil
Refractory bricks
Iron plate
Coke breeze
✅ The correct answer is option D.
The Fourier number (defined as a.t/L²) is used in the analysis of problem involving heat transfer by
Forced convection
Natural convection
Transient conduction
Steady state conduction
✅ The correct answer is option C.
Thermal diffusivity is the most important in heat transfer by
Conduction
Radiation
Condensation
Natural convection
✅ The correct answer is option A.