For an ideal black body Reflectivity = 1 Transmissivity = 1 Absorptivity = 1 Emissivity = 0 TRUE ANSWER : ? YOUR ANSWER : ?
Dropwise condensation occurs on __________ surfaces clean and dirt free smooth clean polished contaminated cooling TRUE ANSWER : ? YOUR ANSWER : ?
The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K₀ + at. where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be W/m None, A is just a number W/m.k² W/m.k TRUE ANSWER : ? YOUR ANSWER : ?
Radiation energy is emitted by all the substances, which are above 0°C 0°K none of the listed here 100°C TRUE ANSWER : ? YOUR ANSWER : ?
Pick out the correct equation. JH = (St)2/3(Pr) = f/2 JH = (St)(Pr)2/3 = f/2 JH = (St)1/3(Pr) = f/2 JH = (St)(Pr)1/3 = f/2 TRUE ANSWER : ? YOUR ANSWER : ?
Fruit juice (a heat sensitive material) can be concentrated in a __________ evaporator. High pressure Falling film Long tube None of these TRUE ANSWER : ? YOUR ANSWER : ?
__________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side. U-tube None of these Single pass, fixed tube sheet Three pass, fixed tube sheet TRUE ANSWER : ? YOUR ANSWER : ?
Heat transfer rate described by Fourier's law will decrease, if the __________ increases. Temperature difference Thickness Heat transfer area Thermal conductivity TRUE ANSWER : ? YOUR ANSWER : ?
In Biot number, the characteristic length used is the ratio of the __________ of the solid. Surface area to volume Perimeter to surface area Surface area to perimeter Volume to surface area TRUE ANSWER : ? YOUR ANSWER : ?
When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as __________ boiling. none of the listed here pool transition film TRUE ANSWER : ? YOUR ANSWER : ?