Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface ?

Related Mcqs:

Pick out the wrong statement?

A. Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection B. The ratio NNu/NRe . Npr is called the Stanton number C. The Peclet number is a measure of the ratio of energy transport by convection to that by conduction D. The Colburn jH … Pick out the wrong statement?Read More...

The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C- 1 respectively. The ambient air is at 30°C and the heat transfer co-efficient between the outer surface of wall and air is 20 W.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is__________________?

A. 165.4 B. 167.5 C. 172.5 D. 175...

LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface area required is the least in the ______________ flow?

A. Parallel B. Mixed C. Counter flow D. Same in either A , B. or C....

With increase in temperature, the thermal conductivity of a gas ___________________?

A. Increases B. Decreases C. Remain same D. May increase or decrease depending on the type of gas...

When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?

A. At high fluid velocity B. At low velocity C. When fluid flows past a smooth surface D. None of these...