Radius and number of turns of a circular coil are 10 cm and 25 respectively. What should be the curcrent through the coil that will produce a magnetic field of `6.28xx10^(-5)Wb*m^(-2)` at its centre ?

Explanation

Radius of the coil,` r=(10)/(2)=5 cm =0.05m,` number of turns `N=25` and magnetic field at the centre of the coil `B=6.28xx 10^(-5)Wb*m^(-2)` .
Now `B=(mu_(o)NI)/(2r)`
`:. I=(2rB)/(mu_(0)r) =(2xx0.05xx(6.28xx10^(-5)))/((4xxpixx10^(-7))xx25=0.2A`