A circular coil of radius having 50 tightly packed turns is suspended so that it can…
PHYSICS · Subjective · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
A circular coil of radius 10cm having 50 tightly packed turns is suspended so that it can rotate freely about a vertical diameter. The coil carries a current of 3.0A and is placed in a uniform horizontal magnetic field of 0.40T. A small mass m is attached to the lowest point of the coil’s rim by means of a light thread so that the weight of the mass provides a counter-torque. In equilibrium the plane of the coil makes an angle of 25∘ with the magnetic field direction.
(a) Obtain an expression for the equality of torques that gives the required mass m in terms of the given quantities.
(b) Calculate the value of m.
(c) If the magnetic field is doubled while all other conditions remain unchanged, find the new equilibrium angle made by the plane of the coil with the field direction.