Gce Model Questions Vol1 2021 Physics Question 35

A rectangular conducting loop of resistance \(R=0.5\) Ω has sides of length \(l=0.30\) m (parallel to a uniform magnetic field) and width \(w=0.12\) m (perpendicular to the field). The loop moves with constant speed \(v\) into the region of the field \(B=0.8\) T, which extends over the width \(w\). The loop has mass \(m=0.020\) kg and is initially at rest outside the field. Determine (i) the speed \(v\) for which the kinetic energy lost by the loop while entering the field equals the electrical energy dissipated as heat in the loop, and (ii) the induced current when the loop is half‑inside the field. Give \(v\) in m s⁻¹ (to two significant figures) and the current in amperes (to two significant figures).