small magnetic needle, which is free to turn slowly in a horizontal plane, is placed at the center of the coil. Show that it will set at an angle A to B where
cot()=4R/n2oa)
Calculate the angle with respect to B at which it reaches equilibrium.
A circular coil of 200 turns of radius a=60mm, total resistance R=2 ohm, and no self inductance is rotated about a vertical diameter with uniform angular velocity =200 rad/s in a horizontal magnetic flux B of 0.25 Tesla. Calculate the average power needed to keep the coil in motion.