1625. In forced circulation, the heating element is injected
Internally
Externally
Both A and B
Neither A nor B
✅ The correct answer is option A.
1628. For evaporation of viscous solution in a multiple effect evaporator, the prefered feeding scheme is
Forward
Backward
Parallel
None of these
✅ The correct answer is option B.
1631. Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is
0.2
0.4
0.6
0.8
✅ The correct answer is option C.
1561. Fouling factor for a heat exchanger is given by (where, U₁ = heat transfer co-efficient of dirty surface U₂ = heat transfer co-efficient of clean surface)
U₁ – U₂
1/U₁ – 1/U₂
1/U₂ – 1/U₁
U₂ – U₁
✅ The correct answer is option B.
1564. Dropwise condensation is promoted on a/an __________ surface.
Glazed
Oily
Coated
Smooth
✅ The correct answer is option B.
1567. Sensible heat of hot industrial flue gases can not be recovered by a/an
Economiser
Regenerator
Ceramic recuperator
None of these
✅ The correct answer is option D.
1570. The critical radius ‘r’ of insulation on a pipe is given by
r = 2k/h
r = k/h
r = k/2h
r = h/k
✅ The correct answer is option B.
1573. The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is
More
Less
Some
Either more or less ; depends on the nature of vapor
✅ The correct answer is option C.
1576. Which of the following is directly concerned with the heat transfer?
Strouhal number
Sherwood number
Euler number
Grashoff number
✅ The correct answer is option D.
1579. Water is normally used as a coolant in the heat exchange equipments mainly because ofits
Abundance & high heat capacity
Low density
Low viscosity
High fluidity
✅ The correct answer is option A.