Questions in Mechanical Properties of Fluids

Select	Question
	A manometer connected to a closed tap reads $4.5\times {{10}^{5}}$ pascal. When the tap is opened the reading of the manometer falls to $4\times {{10}^{5}}$ pascal. Then the velocity of flow of water is
	What is the velocity v of a metallic ball of radius r falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body ? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$).
	Consider the following equation of Bernouilli’s theorem. $P+\frac{1}{2}\rho {{V}^{2}}+\rho gh=K$(constant). The dimensions of $K/P$ are same as that of which of the following
	An incompressible fluid flows steadily through a cylindrical pipe which has radius 2r at point A and radius r at B further along the flow direction. If the velocity at point A is v, its velocity at point B is
	The value of surface tension of a liquid at critical temperature is
	The spherical shape of rain-drop is due to
	Surface tension is due to
	When there is no external force, the shape of a liquid drop is determined by
	Soap helps in cleaning clothes, because
	A pin or a needle floats on the surface of water, the reason for this is