The radius of a soap bubble is blown up to double its value under isothermal conditions.  If 'r' be the initial radius of bubble, and T be the surface tension, then energy spent in doubling the radius is :

Water is flowing continuously  from a tap having an internal diameter 8×10^-3 m.  The water velocity as it leaves the tap is 0.4 ms^-1. The diameter of the water stream at a distance 2 × 10^-1 m below the tap is close to

PQRS is a rectangular frame of copper wire shown in figure. The side RS of the frame is movable.  If a soap film is formed on it then the diameter of the wire to maintain equilibrium will be (given surface tension of soap solution=0.045 N/m and density of copper = 8.96 x 10³ kg/m³  ) 

A cylinder of height 20 m is completely filled with water.  The velocity of efflux of water (in ms^-1 ) through a small hole on the side wall of the cylinder near its bottom is

A body floats in a liquid contained in a beaker.  The whole system as shown in figure falls freely under gravity.  The upthrust on the body is

There is a small hole in a hollow sphere.  The water enters in it when it is taken to a depth of 40 cm under water.  The surface tension of water is The diameter of hole is :

n small drops of radius r, combine to form a bigger drop of the radius R.  If the energy evolved provides K.E to the drop then the speed of the drop will be (density of drop = d and surface tension of liquid = T)

Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly (surface tension of soap solution = 0.03 Nm^-1 )

A man is sitting in a boat, which is floating on a pond.  If the man drinks some water from the pond, the level of water in the pond

Radius of one arm of hydraulic lift is four times of radius of other arm.  What force should be applied on narrow arm to lift 100 kg ?