A circular coil of a wire containing 100 turns each of radius 2cm carries a current of 0.20A. The magnetic field at the centre of the coil is…..

Options

A. `2pixx10^(-4)`
B. `pixx10^(-4)`
C. `3pixx10^(-4)`
D. `10^(-4)`

Answer

A

Explanation

N = 100
`r=2cm=2xx10^(-2)m`
`I=0.20A=2xx10^(-1)A`
Magnetic field at centre,
`B=(mu_(0)NI)/(2R)=(4pixx10^(-7)xx100xx2xx10^(-1))/(2xx2xx10^(-2))`
`thereforeB=2pixx10^(-4)T`