Questions and answers for exam Preparation

MCQs

Total Questions : 2525 | Page 248 of 253 pages

Question 2471. Among liquids, water has a comparatively high value of thermal conductivity, due to its__________________?

Low density
High viscosity
Partial ionisation
Dense structure

Discuss Question

Answer: Option C. -> Partial ionisation
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2472. In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is_________________?

Minimum
Maximum
Zero
Infinity

Discuss Question

Answer: Option C. -> Zero
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2473. If Prandtl number is greater than the Schmidt number, then the____________________?

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

Discuss Question

Answer: Option A. -> Thermal boundary layer lies inside the concentration boundary layer
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2474. LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is __________________?

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Answer: Option D. -> < 1
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2475. Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is __________________?

In the central core of the fluid
Uniformly distributed throughout the fluid
Mainly confined to a thin film of fluid near the surface
None of these

Discuss Question

Answer: Option C. -> Mainly confined to a thin film of fluid near the surface
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2476. Thermal diffusivity is the most important in heat transfer by__________________?

Conduction
Radiation
Condensation
Natural convection

Discuss Question

Answer: Option A. -> Conduction
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2477. Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called_______________?

Radiation
Natural convection
Forced convection
Conduction

Discuss Question

Answer: Option C. -> Forced convection
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 2478. For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area___________________?