During crystallisation, formation of crystal can occur in ______________ solution only?
A. Saturated
B. Supersaturated
C. Under-saturated
D. All A., B. and C.
Chemical Heat Transfer
When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?
When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?
A. At high fluid velocity
B. At low velocity
C. When fluid flows past a smooth surface
D. None of these
Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2.°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the_________________?
Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2.°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the_________________?
A. Higher condensing film co-efficient is desired
B. Condensate is corrosive in nature
C. Lower pressure drop through the exchanger is desired
D. Temperature of the incoming vapor is very high
A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300°C and allowed to cool in natural air. Which one will cool the slowest ?
A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300°C and allowed to cool in natural air. Which one will cool the slowest ?
A. Cube
B. Plate
C. Sphere
D. All will cool at the same rate
A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions? Assume that the conductive heat transfer co-efficient is infinitely large ?
A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions? Assume that the conductive heat transfer co-efficient is infinitely large ?
A. 5 minutes
B. 10 minutes
C. 20 minutes
D. 40 minutes
Presence of a non-condensing gas in a condensing vapour___________________?
Presence of a non-condensing gas in a condensing vapour___________________?
A. Increases the rate of condensation
B. Decreases thermal resistance
C. Is desirable to increase the film co-efficient
D. None of these
The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) ?
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
A process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is_______________?
A process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is_______________?
A. Counter flow with process stream on shell side
B. Counter flow with process stream on tube side
C. Parallel flow with process stream on shell side
D. Parallel flow with process stream on tube side
Natural convection is characterised by__________________?
Natural convection is characterised by__________________?
A. Grashoff number
B. Peclet number
C. Reynolds number
D. Prandtl number
The unit of heat transfer co-efficient is_________________?
The unit of heat transfer co-efficient is_________________?
A. BTU/hr. ft2°F
B. BTU/hr. °F. ft
C. BTU/hr. °F
D. BTU/hr. ft