The dimension of surface tension is :

A mercury manometer is used to measure the static pressure at a point in a water pipe as shown in Fig. The level difference of mercury in the two limbs is $$10$$ $$mm.$$ The gauge pressure at that point is

For laminar flow through a long pipe, the pressure drop per unit length increases.

For a given heat flow and for the same thickness, the temp drop across the material will be maximum for