1. A circular coil of wire consisting of 100 turns, each of radius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil?
The magnitude of the magnetic field at the centre of a circular coil of radius r carrying current I is given by,
For 100 turns, the magnitude of the magnetic field will be,
(current=0.4A, radius = 0.08m, permeability of free space = 410-7 TmA-1)