State the connection between magnetic flux density $B$ and magnetic flux $\phi$, and define any other symbols you use.
A large horseshoe magnet has a uniform magnetic field in the gap between its poles. Outside the gap between the poles, the magnetic field is zero. A small Hall probe is moved at constant speed along the line XY, which lies midway between, and parallel to, the faces of the magnet poles, as shown in Fig. 5.1.
State Faraday’s law that describes electromagnetic induction.
In place of the Hall probe in (b), use a small flat coil of wire. Move the coil along the line $XY$ at constant speed. The plane of the coil is parallel to the faces of the magnet poles. On the axes in Fig. 5.3, sketch a graph to show how the induced e.m.f. $E$ varies with time $t$ in the coil.