The amount of energy required to form a soap bubble of radius $$2 \mathrm{~cm}$$ from a soap solution is nearly: (surface tension of soap solution $$=0.03 \mathrm{~N} \mathrm{~m}^{-1}$$ )

The venturi-meter works on :

Let a wire be suspended from the ceiling (rigid support) and stretched by a weight $$W$$ attached at its free end. The longitudinal stress at any point of cross-sectional area $$A$$ of the wire is :

Two copper vessels A and B have the same base area but of different shapes. A takes twice the volume of water as that B requires to fill upto a particular common height. Then the correct statement among the following is :