1629. Which of the following is generally considered as opaque surface towards radiations?
Gases
Solids
Liquids
Both B and C
✅ The correct answer is option D.
1632. Vent pipes are provided in a condenser to
Remove non-condensable gases
Purge the condenser
Facilitate easy cleaning of tubes
None of these
✅ The correct answer is option A.
1634. The purpose of floating head in a heat exchanger is to
Avoid buckling of tubes
Provide support for tubes
Decrease the pressure drop
Facilitate its lengthening, if needed
✅ The correct answer is option A.
1636. For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area
Increases
Decreases
Remains constant
Passes through a maxima
✅ The correct answer is option D.
1601. __________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side.
Single pass, fixed tube sheet
U-tube
Three pass, fixed tube sheet
None of these
✅ The correct answer is option B.
1603. Reason for operating an evaporator in multiple effect is to secure
Increased steam economy
Decreased steam consumption
Both A and B
Increased capacity
✅ The correct answer is option C.
1605. A perfect black body is a perfect __________ of radiation.
Absorber
Emitter
Both A & B
Neither A nor B
✅ The correct answer is option C.
1607. In SI units, fouling factor is expressed in
m²°K/W
W/m²°K
m²°K
m°K/W
✅ The correct answer is option A.
1609. In case of a supercooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is
More
Less
Same
More or less; depends on the nature of solution
✅ The correct answer is option A.
1611. Which of the following has the minimum thermal conductivity?
Nitrogen
Steel
Carbon black
Tar
✅ The correct answer is option A.