A circular coil of wire consisting of 100 turns, each of radius 4.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil ?

Explanation

For a current carrying thin circular coil of radius R with N no. of identical tightly wound turns, magnetic field produced at the centre is,
`B=(mu_(0)NI)/(2R)`
`thereforeB=((4pixx10^(-7))(100)(0.4))/((2)(0.08))`
`thereforeB=pixx10^(-4)T=3.14xx10^(-4)T`