Question

Explain how electric and magnetic fields are related to the current in the wire. Why is the electric field in phase with the magnetic field?

Answer 1

The direction of electric field is in the same direction of current.

But the direction of magnetic field lines are concenric cricles around the wire.

If we take our right hand thumb finger in the direction of current then curl of our fingers indicates the direction of magnetic field lines.

we know, E = I*rho/A

E is proportional I

we know, B = mue*I/(2*pi*r)

and B is also proprtional to I

so, Both E and B are proportional to I. so, E and B are in phase.