A moving coil meter has a coil of 60 turns wound on to a former of effective length 22.5 mm and diameter 15 mm. If the flux density in the air gap is 0.2 T, and the coil current is 0.1 mA. Calculate
(a) the force acting on each side of the coil, and
(b) the restoring torque exerted by the springs for the resulting deflection of the coil.