The magnet is moved towards the coil with speed '$$\mathrm{V}$$'. The induced e.m.f. in the coil is '$$\mathrm{e}$$'. The magnet and the coil move away from one another each moving with speed '$$\mathrm{V}$$'. The induced e.m.f. in the coil is

A transformer has 20 turns in the primary and 100 turns in the secondary coil. An ac voltage of $$\mathrm{V}_{\text {in }}=600 \sin 314 \mathrm{t}$$ is applied to primary terminal of transformer. Then maximum value of secondary output voltage obtained in volt is

SI units of self inductance is

An air craft of wing span $$40 \mathrm{~m}$$ files horizontally in earth's magnetic field $$5 \times 10^{-5} \mathrm{~T}$$ at a speed of $$500 \mathrm{~m} / \mathrm{s}$$. The e.m.f. generated between the tips of the wings of the air craft is