In sub-cooled boiling, Temperature of the heating surface is more than the boiling point of the liquid Very large vapour space is necessary Temperature of the heating surface is less than the boiling point of the liquid Bubbles from heating surface are absorbed by the mass of the liquid TRUE ANSWER : ? YOUR ANSWER : ?
If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will Decrease by 22 Increase by 1.8 times Remain unchanged Increase by 216 TRUE ANSWER : ? YOUR ANSWER : ?
Calburn analogy is applicable for the value of Prandtl number from 0.001 to 1 0.6 to 120 0.5 to 5 120 to 400 TRUE ANSWER : ? YOUR ANSWER : ?
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 48000 24000 60000 6000 TRUE ANSWER : ? YOUR ANSWER : ?
Film condensation is promoted on a/an __________ surface. dirty clean & smooth coated oily TRUE ANSWER : ? YOUR ANSWER : ?
Open pan evaporators are preferred to be used, when the solution to be concentrated is Highly viscous Scaling Corrosive Salty TRUE ANSWER : ? YOUR ANSWER : ?
The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation. Decreases Remains constant Increases May increase or decrease ; depends on the material TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following situations can be approximated to a steady state heat transfer system? A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmosheric air at 35°C A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C 10 kg of dry saturated steam at 8 kgf/cm² flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C TRUE ANSWER : ? YOUR ANSWER : ?
What is the unit of thermal conductivity ? Kcal/hr. m² °C Kcal/hr. °C Kcal/hr.m Kcal/hr.m.°C TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following has the lowest overall heat transfer co-efficient? Water Molten sodium Air Dowtherm TRUE ANSWER : ? YOUR ANSWER : ?