Question

A long straight wire carries a current of 12 amperes. Calculate the intensity of the magnetic field at a distance of 48 cm from it

Answer 1

current through the long straight wire, I = 12A

seperation between observation point to wire , r = 48cm = 0.48 m

from Ampere's circuital law we get,

$B=\frac{\mu_0I}{2\pi r}$

here, $\mu_0$ = 4π × 10^-7 Tm/A

so, B = (4π × 10^-7 × 12)/(2π × 0.48)

= (1/2) × 10^-5

= 5 × 10^-6 T

hence, intensity of the magnetic field at a distance of 48cm from long straight wire is 5 × 10^-6 T