A. On polished surfaces
B. On rough surfaces
C. In the absence of agitation
D. None of these
Related Mcqs:
- The heat flux in the nucleate boiling regimes is proportional to (where, ΔT = excess temperature) ?
A. (ΔT)2
B. (ΔT)4
C. (ΔT)3
D. √(ΔT) - In case of _______________ boiling, the liquid temperature is below the saturation temperature and the boiling takes place in the vicinity of the heated surface?
A. Nucleate
B. Local
C. Pool
D. Saturated - Boiling point elevation for a strong and concentrated solution is found by Duhring’s rule, which states that at the same pressure, the boiling point of a solution is a linear function of the _______________ of pure water?
A. Boiling point
B. Dynamic viscosity
C. Kinematic viscosity
D. Density - Boiling of milk in an open vessel is an example of ______________ boiling?
A. Film
B. Sub-cooled
C. Saturated nucleate
D. None of these - Dropwise condensation is promoted on a/an ______________ surface?
A. Glazed
B. Oily
C. Coated
D. Smooth - Film condensation is promoted on a/an _______________________ surface?
A. Oily
B. Coated
C. Clean & smooth
D. Dirty - When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as ___________________ boiling?
A. Pool
B. Nucleate
C. Transition
D. Film - A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time ___________________?
A. t = 283 s
B. t = 356 s
C. t = 400 s
D. t = 800 s - Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because___________________?
A. Convection becomes important
B. Conduction becomes important
C. Radiation becomes important
D. Sub-cooled boiling occurs - In case of _____________ boiling, the bubbles formed on a submerged hot surface get absorbed in the mass of the liquid?
A. Nucleate
B. Pool
C. Low pressure
D. None of these
