Question

A current loop of arbitrary shape lies in a uniform magnetic field B. Show that the net magnetic force acting on the loop is zero.

Answer 1

F₁ = Force on AD = iℓB inwards

F₂ = Force on BC = iℓB inwards

They cancel each other

F₃ = Force on CD = iℓB inwards

F₄ = Force on AB = iℓB inwards

They also cancel each other.

So the net force on the body is 0.