For an ideal black body______________________?
A. Absorptivity = 1
B. Reflectivity = 1
C. Emissivity = 0
D. Transmissivity = 1
Month: March 2019
For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a _______________ evaporator?
For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a _______________ evaporator?
A. High pressure
B. Vacuum
C. Backward feed
D. None of these
Leidenfrost point is a term concerned with the____________________?
Leidenfrost point is a term concerned with the____________________?
A. Condensation of the saturated vapor on a cold surface
B. Concentration of a corrosive solution by evaporation
C. Heat transfer between two highly viscous liquids
D. Boiling of a liquid on a hot surface
Which of the following is not used as a medium for high temperature heating ?
Which of the following is not used as a medium for high temperature heating ?
A. Dowtherm
B. Mercury
C. Liquid metal (e.g. molten sodium)
D. Fused salts (e.g., an eutectic mixture of 53% KNO3, 40% NaNO2and 7% NaNO3)
The inside heat transfer co-efficient in case of turbulent flow of liquid in the tube side in a 1-2 shell and tube heat exchanger is increased by ______________ times, when the number of tube passes is increased to 8?
The inside heat transfer co-efficient in case of turbulent flow of liquid in the tube side in a 1-2 shell and tube heat exchanger is increased by ______________ times, when the number of tube passes is increased to 8?
A. 20.8
B. 40.8
C. 40.4
D. 20.4
In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred_________________?
In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred_________________?
A. Through a metallic wall
B. By direct contact of hot flue gas with air
C. By heating an intermediate material (like chequor bricks) and then heating the air from this
hot material
D. None of these
A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is__________________?
A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is__________________?
A. 6000
B. 24000
C. 60000
D. 48000
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is______________?
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is______________?
A. 1.66
B. 88.66
C. 3.66
D. Dependent on NRe only
Which characteristic of a fluid is not important in deciding its route in a shell and tube heat exchanger ?
Which characteristic of a fluid is not important in deciding its route in a shell and tube heat exchanger ?
A. Corrosiveness
B. Fouling characteristic
C. Viscosity
D. None of these
What is the absorptivity of a black body?
What is the absorptivity of a black body?
A. 1
B. 0
C. 0.78
D. 0.95