Question

Two long parallel conductors carry currents i and 2i in same direction the magnetic induction at the point exactly midway between them is b if the current in the first conductor is reversed in direction

Answer 1

If the force works in the same direction as the I and 2I then the first wire will show,

B1 will be μ0 * I / 2 * pie * r

Fz/l = μ0 * I * 2I / w * pie * d

They will repeal each other but when the force of first is reverse the distance will decrease.