Calculate the magnetic field due to a circular coil of `250` turns and of diameter `0*1m`, carrying a current of `7A` (i) at the center of the coil (ii) at a point on the axis of the coil at a distance `0*12m` from the center of the coil.

Answer

(i) `2*2xx10^-2T` (ii) `1*25xx10^-3T`

Explanation

(i) `B=(mu_0)/(4pi)(2pinI)/(r)`
`=(10^-7xx2xx(22//7)xx250xx7)/((0*1//2))=2*2xx10^-2T`
(ii) `B=(mu_0)/(4pi)(2pinIa^2)/((a^2+x^2)^(3//2))`
`=(10^-7xx2xx(22//7)xx250xx7xx(0*1//2)^2)/([(0*1//2)^2+(0*12)^2]^(3//2))`
`=1*25xx10^-3T`