Couette flow is characterized by

Which of the following statement are TRUE, when the cavitation parameter $$\sigma = 0?$$
(i) The local pressure is reduced to vapor pressure.
(ii) Cavitation starts
(iii) Boiling of liquid starts
(iv) Cavitations stops

A brick wall $$\,\left( {k = 0.9{W \over {m.K}}} \right)$$ of thickness $$0.18$$ $$m$$ separates the warm air in a room from the cold ambient air. On a particular winter day, the outside air temperature is −$${5^ \circ }C.\,$$ and the room needs to be maintained at $${27^ \circ }C.\,$$ The heat transfer coefficient associated with outside air is $$20\,\,W/{m^2}K.$$ Neglecting the convective resistance of the air inside the room, the heat loss, in $$\left( {{W \over {{m^2}}}} \right)$$ is

The ratio of momentum diffusivity $$\left( \upsilon \right)$$ to thermal diffusivity $$\left( \alpha \right),$$ is called