power lines have a limit on the maximum size of the electric fieldthey produce. in most states, a maximum of 5kN/C at about 20 m fromthe wires is allowed. This is quite large compared to the Earth'sfair-weather electric field of about 100 N/C. Assume that thecharge on the wire is static (not true, but a simplifcation here)and use the formula for the electric field for a wire : E=(2kλ)/(r) to determine how much charge per unit length is onthe wire.