Heat Transfer MCQ Questions & Answers

41

The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the

A) Solution has an elevation of boiling point B) Evaporators operate under vacuum C) Evaporators opreate at atmospheric pressure D) None of these

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

42

Choose the most important factor on which the heat conducted through a wall in a unit time will depend on?

A) Thickness of the wall B) Area of the wall perpendicular to heat flow C) Material of the wall D) Temperature difference between the two surfaces of the wall

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

43

The actual temperature drop across the heating surface in an evaporator depends on the

A) Feed B) Depth of liquid over heating surface C) Pressure difference between steam chest and vapour space D) All of the above

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

44

Kg of liquid evaporated per hour in an evaporator is defined as its

A) Capacity B) Economy C) Steam load D) None of these

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

45

Mechanical recompression evaporation is used in the production of

A) Alcohol B) Distilled water C) Salt D) Fruits jam

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

46

Reason for operating an evaporator in multiple effect is to secure

A) Increased steam economy B) Decreased steam consumption C) Both A and B D) Increased capacity

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

47

In the equation Q = UAΔt; Δt is

A) Geometric mean temperature difference B) Arithmetic mean temperature difference C) Logarithmic mean temperature difference D) The difference of average bulk temperatures of hot and cold fluids

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

48

If Prandtl number is greater than the Schmidt number, then the

A) Thermal boundary layer lies inside the concentration boundary layer B) Concentration boundary layer lies inside the thermal boundary layer C) Thermal & concentration boundary layers are of equal thickness D) Hydrodynamic(i.e., momentum)boundary layer is thicker than the other two

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

49

Pick out the wrong statement.

A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature C) Double pipe heat exchangers are mostly used in the field of refrigeration D) Finned tube heat exchangers are suitable for heating air by steam

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

50

Grashoff number, which is defined as g.β(T_s - T_∞) ρ².L³/μ², is proportional to the ratio of buoyancy force to __________ force.

A) Viscous B) Elastic C) Inertial D) None of these

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

Heat Transfer MCQ Questions & Answers | Chemical Engineering