# Heat and Mass Transfer Objective Questions with Answers

## Heat and Mass Transfer Objective Questions

These Heat and Mass Transfer Objective Questions are very important for the competitive exams like SSC JE, RRB, GATE, ISRO, DRDO, and all other competitive exams.

All these Heat and Mass Transfer Objective Questions are from the previous years’ papers of one of the exams mentioned before. Read More- Strength of Materials Objective Questions

1. The fraction of radiative energy leaving one surface that strikes the other surface is called?

B. View factor

D. The emissive power of the first surface

Correct Answer is C

2. Prandtl number of a flowing fluid greater than unity indicates that hydrodynamic boundary layer thickness is –

A. greater than the thermal boundary layer thickness

B. equal to the thermal boundary layer thickness

C. greater than the hydrodynamic boundary layer thickness

D. independent of thermal boundary layer thickness

Correct Answer is A

3. Which one of the following numbers represents the ratio of kinematic viscosity to the thermal diffusivity?

A. Mach Number

B. Nusselt Number

C. Prandtl Number

D. Grashoff Number

Correct Answer is C

Prandtl Number is named after the German physicist Ludwig Prandtl.

4. Which one of the following non-dimensional numbers are used for transition from laminar to turbulent flow in free convection?

A. Reynolds Number

B. Peclet Number

C. Rayleigh Number

D. Grashoff Number

Correct Answer is D

Grashoff Number: It is the ratio of the buoyancy to the viscous force acting on a fluid.

5. Heat transfer takes place according to

A. Zeroth law of thermodynamics

B. 1st Law of thermodynamics

C. 2nd Law of thermodynamics

D. 3rd Law of thermodynamics