Question

A flat circular coil with 40 loop of wire has a diameter of 32cm what current most flow in it's wire to produce a field in air of 3.0x10^-4 w/m2 or centre

Answer 1

Answer

No. Of loops N=40

Radius R=0.16m

Magnetic field on centre

$B=3.0*10^{-4 }W/m^2$

The current flow in loop is

$I=\frac{RB4\pi}{N\mu_0 2\pi }$

Putting all values

$I=\frac{0.16\times3\times10^{-4}}{40\times10^{-7}\times2\times3.14}$

$I=1.91A.$

So current in wire is 1.91A.