CBSE · Class 12 · Physics · Moving Charges and MagnetismWhat is the force per unit length between two long parallel straight conductors carrying currents in the same direction?

The magnetic force per unit length between two long parallel straight conductors placed at a distance $d$ apart and carrying currents $I_1$ and $I_2$ in the same direction is given by the formula $F/l = \frac{\mu_0 I_1 I_2}{2\pi d}$. Because the currents flow in the same direction, the magnetic forces are attractive in nature, causing the two conductors to pull towards each other.