NEET-XII-Physics
04: Moving Charges And Magnetism
- #1A 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?
Ans : Number of turns on the circular coil, n = 100
Radius of each turn, r = 8.0 cm = 0.08 m
Current flowing in the coil, I = 0.4 A
Magnitude of the magnetic field at the centre of the coil is given by the relation,

Where,
= Permeability of free space
= 4``\pi`` × 10-7 T m A-1

Hence, the magnitude of the magnetic field is 3.14 × 10-4 T.