Question

If same current 'I' is flowing through two parallel wires, separated by the distance 'b' in air, then force acting per unit length of wires will be `(mu_0= "permeability of free space")`____________.

Options

• `(mu_0 I^2)/(4pib)`

• `(mu_0 I)/(4pib^2)`

• `(mu_0  I^2)/(4pi  b^2)`

• `mu_0/(4pi) xx (2I^2)/b`

Answer 1

If same current 'I' is flowing through two parallel wires, separated by the distance 'b' in air, then force acting per unit length of wires will be

`mu_0/(4pi) xx (2I^2)/b`.

Explanation:

`"F/l = mu_0/(4pi) (2I_1 I_2)/r`

Here, r = b and I₁ = I₂ = I

`therefore F/l = (mu_0 2I^2)/(4pib)`