The ratio of the terminal velocities of two drops of radii R and R/2 is

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 closed compartment containing gas is moving with some acceleration in horizontal direction.  Neglect effect of gravity.  Then the pressure in the compartment is

Water rises in a capillary tube upto a height of 10 cm whereas mercury depresses in it by 3.42 cm.  If the angle of contact and density of mercury are 135^o and 13.6 gm/cc respectively, then the ratio of the surface tension of water and mercury will be :

Water from a tap emerges vertically downwards with an initial speed of 1.0 ms^-1 .  The cross-sectional area of the tap is 10^-4 m².  Assume that the pressure is constant throughout the stream of water, and that the flow is steady.  The cross-sectional area of the stream 0.15 m below the tap is

One large soap bubble of diameter D breaks into 27 bubbles having surface tension T.  The change in surface energy is

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 )

The potential energy possessed by a soap bubble, having surface tension equal to 0.04 Nm^-1 of diameter 1 cm, is

A liquid X of density 3.36 g/cm³ is poured in the right arm of a U-tube, which contains Hg.  Another liquid Y is poured in left arm with height 8 cm, upper levels of X and Y are same.  What is density of Y ?

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.