A body attached to one end of a string performs motion along a vertical circle. Its centripetal acceleration, when the string is horizontal, will be [$$\mathrm{g}=$$ acceleration due to gravity]
A coil has an area $$0.06 \mathrm{~m}^2$$ and it has 600 turns. After placing the coil in a magnetic field of strength $$5 \times 10^{-5} \mathrm{Wbm}^{-2}$$, it is rotated through $$90^{\circ}$$ in 0.2 second. The magnitude of average e.m.f induced in the coil is
$$\left[\cos 0^{\circ}=\sin 90^{\circ}=1 \text { and } \sin 0^{\circ}=\cos 90^{\circ}=0\right]$$
. If the current of '$$I$$' A gives rise to a magnetic flux '$$\phi$$' through a coil having '$$N$$' turns then mangetic energy stored in the medium surrounding the coil is
An ideal gas with pressure $$\mathrm{P}$$, volume $$\mathrm{V}$$ and temperature $$\mathrm{T}$$ is expanded isothermally to a volume $$2 \mathrm{~V}$$ and a final pressure $$\mathrm{P}_{\mathrm{i}}$$. The same gas is expanded adiabatically to a volume $$2 \mathrm{~V}$$, the final pressure is $$\mathrm{P}_{\mathrm{a}}$$. In terms of the ratio of the two specific heats for the gas '$$\gamma$$', the ratio $$\frac{P_i}{P_a}$$ is