Question

The linear charge densities on two straight parallel long linear charges are λ1 and λ2. Obtain the formula for force acting per unit length between them.

Answer 1

Answer:

Electric field due to infinitely long wire of linear charge density at R distance is given by,

it is given that , another infinity long wire is placed at R distance parallel to first wire. so, find charge on the wire.

as we know, , where l is length of wire.

so, charge on 2nd wire,

from formula, F = QE

here, and

so, force experienced by 2nd wire , F =

hence, force per unit length,