A circualr coil, having 100 tures of wire, of readius (nearly) 20cm each, lies in the XY plane with its centre at the origin of co-ordinates. Find the magnetic field, at the point `(0,0,20sqrt3Cm)`, when this coil carries a current of `((2)/(pi))A`.

Explanation

`B=(mu_(0))/(4pi)(2pinIa^(2))/((a^(2)+x^(2))^(2//3))`
`=(10^(-7)xx2pixx100xx(2)/(pi)xx(20xx10^(-2))^(2))/[(400+1200)xx10^(-4)]^(3//2)=(10^(-7)xx200xx400xx10^(-4))/(64000xx10^(-6))`
`=(8xx10^(-7))/(64xx10^(-3))=(1)/(8)xx10^(-4)=0.125xx10^(-4)=1.25xx10^(-5)T`.