Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is________________?
A. 0.1
B. > 1
C. < 1
D. 1
Chemical Heat Transfer
The type of liquor circulation system to be ‘ employed in evaporators (viz. natural or forced circulation) is determined mainly by the ______________ of the liquid?
The type of liquor circulation system to be ‘ employed in evaporators (viz. natural or forced circulation) is determined mainly by the ______________ of the liquid?
A. Viscosity
B. Density
C. Thermal conductivity
D. Corrosive nature
For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would ?
For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would ?
A. Decrease
B. Increase
C. First decrease and then increase
D. First increase and then decrease
In a backward feed multiple effect evaporator ___________________ ?
In a backward feed multiple effect evaporator ___________________ ?
A. Feed is introduced in the first effect
B. Feed flows from low pressure to high pressure
C. No pumps are required between successive effects
D. None of these
The sum of reflectivity and absorptivity for an opaque body is equal to____________________?
The sum of reflectivity and absorptivity for an opaque body is equal to____________________?
A. 0.5
B. 1
C. 0
D. 2
Steam is routed through the tube in case of a ______________ evaporator?
Steam is routed through the tube in case of a ______________ evaporator?
A. Basket type
B. Horizontal tube
C. Short tube vertical
D. Long tube vertical
Multiple effect evaporation is generally recommended, when the______________________?
Multiple effect evaporation is generally recommended, when the______________________?
A. Large scale evaporation of liquor is needed
B. Corrosive liquids are to be concentrated
C. Fuel is cheaply available
D. Evaporation on small scale is to be done
1 BTU/hr.ft.°F is equal to _____________ kcal/hr. m.°C?
1 BTU/hr.ft.°F is equal to _____________ kcal/hr. m.°C?
A. 1.49
B. 1
C. 4.88
D. None of these
A _____________ surface has the maximum thermal emissivity out of the following ?
A _____________ surface has the maximum thermal emissivity out of the following ?
A. Black & smooth
B. Black & rough
C. White & smooth
D. White & rough
A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case ?
A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case ?
A. The cooling rate will be the same for the two spheres and hence the two spheres will have
equal temperatures at any instant
B. Both the spheres will emit equal amount of radiation per unit time in the beginning
C. Both will absorb equal amount of radiation from the surrounding in the beginning
D. Both B. & C.