Home
About Us
Contact Us
Privacy Policy
Search
Home
→
Chemical Heat Transfer
→
The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) ?
Related MCQs
Analogy between mass and heat transfer is not applicable in case of__________?
An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is__________?
Steady state one dimensional heat flow by conduction as given by Fourier’s low does not assume that__________?
Heat transfer co-efficient (h1) for liquids increases with__________?
Multiple effect evaporators ar used to__________?
In natural convection heat transfer, the correlating parameter is the__________?
Correction is applied to LMTD for __________ flow?
Increasing the liquor level in the evaporator results in the__________?
In case of a shell and tube heat exchanger, the minimum and maximum baffle spacing is respectively (where, D = inside diameter of the shell) ?
Double pipe heat exchangers are used__________?
A body is called grey if the monochromatic emissivity of the body is__________?
While the total emissivity of a perfect black body is unity, the same for a real body is__________?
Crystal size in a continuous crystalliser depends upon the__________?
Boiling of milk in an open vessel is an example of __________ boiling?
Black liquor generated during paper manufacture is concentrated in a__________?
What is Nusselt number ?
In the equation Q = UAΔt; Δt is__________?
For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in__________?
Hot water (0.01 m3 /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.05 m3/min) of density 800 kg/m3 and specific heat of 2 kJ/kg.K enters at 20°C. The log mean temperature difference in °C is approximately ?
Graetz number is given by__________?
Reynold’s analogy states that__________?
Which of the following has the minimum thermal conductivity ?
For an ideal black body__________?
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?
Leidenfrost point is a term concerned with the__________?
Which of the following is not used as a medium for high temperature heating ?
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?
In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred__________?
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__________?
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is__________?
Which characteristic of a fluid is not important in deciding its route in a shell and tube heat exchanger ?
What is the absorptivity of a black body?
Economy of a multiple effect evaporator is not influenced much by the__________?
Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube__________?
In case of evaporators, liquid entrainment results primarily due to__________?
Heat exchangers operating, when the asymptotic range is reached, ?
In counter flow compared to parallel flow, ?
Mode of heat transfer involved in the cooling of air cooled internal combustion engine is__________?
In a single effect evaporator, the economy is__________?
Small scale evaporation is done in a__________?
In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always__________?
Low thermal conductivity of heat insulating materials is due to its__________?
Low thermal conductivity of heat insulating materials is due to its__________?
In case of a vertical tube evaporator, with increase in the liquor level, the__________?
The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the__________?
Thermal diffusivity is given by__________?
In a forward feed multiple effect, the pressure build up will be__________?
Which of the following has the minimum absorptivity ?
Convective heat transfer, in which heat is transferred by movement of warmed matter is described by__________?
If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is__________?
In an extended surface heat exchanger, fluid having lower co-efficient__________?
The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) ?
A. K/h0
B. 2K/h0
C. h0/K
D. h0/2K
Correct Answer:
K/h0
✔
Last Updated:
March 03, 2019