Although the evidence is weak, there has been concern in recent years over possible health effects from the magnetic fields generated by electric transmission lines. a typical high-voltage transmission line is 20 m above the ground and carries a 200 a current at a potential of 110 kv. what is the magnetic field strength on the ground directly under such a transmission line?

The concept necessary to develop this exercise is that of a magnetic field on a surface. The magnetic field is a tool to describe how a magnetic force is distributed in the space around and within something magnetic.

It can be defined as,

Where,

R= The distance from the point

I = Current

Permeability constant in free space

Our values are given as,

Replacing ,

Therefore the magnetic field strength on the ground directly under such a transmission line is