(i) Starting from the expression for the magnetic force on a straight conductor…
PHYSICS · Subjective · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
(i) Starting from the expression for the magnetic force on a straight conductor carrying current, derive an expression for the torque acting on a rectangular coil of N turns, area A, carrying a current I when it is placed in a uniform magnetic field B making an angle θ with the normal to the plane of the coil.
(ii) Show that the torque becomes independent of the shape of the coil if its area is kept the same.
(iii) Using your result from part (i), obtain the condition for which the coil experiences no restoring couple when displaced by a small angle in the field.