Twio thin long parallel wires seprated byb a distance b are carrying a current i ampere each . The magnitude of the force per unit length excrted by one wire on . The other is

Options

A. `(mu_0i^2)/(b^2)`
B. `(mu_0i^2)/(2pib)`
C. `(mu_0i)/(2pib)`
D. `(mu_0i)/(2pib^2)`

Answer

b

Explanation

Force per unit length between two wires carrying currents `i_1`
and `i_2` at distance r is given by
`F/l=(mu_0)/(2pi) (i_1i_2)/r`
Here, `i_1=i_2=i and r=b`
`F/l=(mu_0i^2)/(2pib)`