hf = hd
hf > hd
hf < hd
hf could be greater or smaller than hd
✅ The correct answer is option C.
Engineering MCQs
An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a
Boiler
Heat exchanger
Recuperator
Regenerator
✅ The correct answer is option B.
Thermal conductivity of a gas at low density, __________ with increase in temperature.
Decreases
Increases
Remains unchanged
May increase or decrease; depends on the gas
✅ The correct answer is option B.
The equation, Nst = f/2, is the __________ analogy.
Colburn
Reynolds
Prandtl
None of these
✅ The correct answer is option B.
Tubes are held between top and bottom tube sheets in Calenderia type evaporator by keeping
Both the tube sheets fixed
Both the tube sheets floating
The top tube sheet floating and bottom tube sheet fixed
The top tube sheet fixed and the bottom tube-sheet floating
✅ The correct answer is option A.
Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer.
Grashoff
Reynolds
Both A & B
Prandtl & Grashoff
✅ The correct answer is option D.
What is the absorptivity of a black body?
1
0
0.78
0.95
✅ The correct answer is option A.
Kg of liquid evaporated per hour in an evaporator is defined as its
Capacity
Economy
Steam load
None of these
✅ The correct answer is option A.
In a heat exchanger, the rate of heat transfer from the hot fluid to the cold fluid
Varies directly as the area and the LMTD
Directly proportional to LMTD and inversely proportional to the area
Varies as square of the area
None of these
✅ The correct answer is option A.
Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer.
Grashoff
Biot
Stantan
Reynolds
✅ The correct answer is option A.