A current of 0.5 A is passed through winding of a long solenoid having 400 turns. The magnetic flux linked with each turn is $3 \times 10^{-3} \mathrm{~Wb}$. The self inductance of the solenoid is

Identify the correct figure which shows the relation between the height of water column in a capillary tube and the capillary radius.

The escape velocity from earth surface is $11 \mathrm{~km} / \mathrm{s}$. The escape velocity from a planet having twice the radius and same mean density as earth is

A magnetic intensity of $500 \mathrm{~A} / \mathrm{m}$, produces a magnetic flux of $2.4 \times 10^{-5} \mathrm{~Wb}$ in an iron bar of cross-sectional area $0.4 \mathrm{~cm}^2$. The magnetic permeability of the iron bar is