A coil of 50 turns and 10cm diameter is made out of a wire of resistivity `2 xx 10^(-6) Omega cm` and cross sectional radius 0.1mm. The coil is connected to a source of EMF `10 V` and of negligible internal resistance.
(a) Find the current through the coil
(b) What must be potential difference across the coil so as to nullify the horizontal component of earth's magnetic field, `0.314 xx 10^(-4) T` at the centre of the coil. How should the coil be placed to achieve. this result?

Answer

[(a) 1A; (b) 0.5V, coil is placed in a plane normal to magnetic meridian].