The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) ?

Byadmin March 2, 2019August 24, 2021

The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) ?

A. K/h0
B. 2K/h0
C. hi/K
D. 2hi/K

Chemical Heat Transfer

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

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

Read More If Prandtl number is greater than the Schmidt number, then the____________________?
Chemical Heat Transfer

Thermal conductivities of most of the liquids _______________ with rise in temperature?

Thermal conductivities of most of the liquids _______________ with rise in temperature?

A. Increases
B. Decreases
C. Remains unchanged
D. May increase or decrease; depends on the liquid

Read More Thermal conductivities of most of the liquids _______________ with rise in temperature?
Chemical Heat Transfer

For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is________________?

For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is________________?

A. 1.26 h1
B. 0.794 h1
C. 0.574 h1
D. 1.741 h1

Read More For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is________________?
Chemical Heat Transfer

Boiling point elevation of an ideal solution_______________?

Boiling point elevation of an ideal solution_______________?

A. Increases rapidly with temperature rise
B. Decreases rapidly with temperature rise
C. In independent of pressure
D. Both B. and C.

Read More Boiling point elevation of an ideal solution_______________?
Chemical Heat Transfer

The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by__________________?

The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by__________________?

A. Painting the surface black
B. Painting the surface white (with aluminium paint)
C. Giving the surface a mirror finish
D. Roughening the surface

Read More The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by__________________?
Chemical Heat Transfer

Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?

Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?

A. Vertical heat exchanger with steam on tube side
B. Vertical heat exchanger with steam on shell side
C. Horizontal heat exchanger with steam on tube side
D. Horizontal heat exchanger with steam on shell side

Read More Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?

Similar Posts