A current of `0.1 A` circulates around a coil of 100 turns and having a radius equal to `5 cm`. The magnetic field set up at the centre of the coil is
(`mu_(0)=4pixx10^(-7)` weber/amper-metre)

Options

A. `5pixx10^(-5)T`
B. `8pixx10^(-5)T`
C. `4pixx10^(-5)T`
D. `4pixx10^(-5)T`

Answer

C

Explanation

Magnetic field at the centre of circular coil of N turns is given by
`B=(mu_(0)Ni)/(2r)=(4xx10^(-7)xx100xx0.1)/(2xx5xx10^(-2))=4pxx10^(-6)T`