Heat Transfer

1. What is the geometric mean of two heat transfer areas A₁ and A₂ ?

1. 
2. 
3. 
4. 

2. Heat waves

1. can not pass through vacuum.
2. travel in straight line.
3. can be reflected by a mirror.
4. both (b) and (c).

3. Reynold’s analogy states that

1. N_st α f
2. N_st α N_Re
3. N_Nu α f
4. N_Re α f

4.Fourier’s law applies to the heat transfer by

1. convection
2. radiation
3. conduction
4. all (a), (b) & (c)

5.In the equation Q = UAΔt; Δt is

1. geometric mean temperature difference.
2. arithmetic mean temperature difference.
3. logarithmic mean temperature difference.
4. the difference of average bulk temperatures of hot and cold fluids.

Check Your Answers Here 

1. 1    
2. 4
3. 1
4. 1
5. 3

1. Fourier’s law applies to the heat transfer by

1. convection
2. radiation
3. conduction
4. all (a), (b) & (c)

2. When vaporization takes place directly at the heating surface, it is called

1. Film Boiling
2. Nucleate Boiling
3. Vapor Boiling
4. None of these

3. The thermal conductivity of Non-metallic solid (amorphous) , —————— with increase in temperature

1.  increases
2.  decreases
3. remains constant
4. first decreases upto certain temperature then increases

4. Shell side pressure drop in a shell and tube heat exchanger does not depend upon the

1. baffle spacing & shell diameter.
2. tube diameter & pitch.
3. viscosity, density & mass velocity of shell side fluid.
4. none of these.

5.  The steam ejector is used to

1. remove condensate from the steam pipelines
2. create vacuum.
3. superheat the steam.
4. none of these.

Check Your Answers Here 

1. 3
2. 3
3. 1
4. 4
5. 2