(a)[2]
State what the term magnetic field means.
(b(i))[1]
On Fig. 9.1, shade the face of the foil on which electrons first gather.
(b(ii))[3]
Explain why electrons do not keep accumulating on the face you shaded.
(c(i))[1]
The Hall voltage $V_{H}$ produced across the foil in (b) is given by $V_{H} = \frac{BI}{ntq}$ where $I$ is the current in the foil. State the meaning of $n$.
(c(ii))[1]
From the letters shown on Fig. 9.1, identify which distance represents $t$.
(d)[1]
Suggest why, in practice, Hall probes are usually made from a semiconductor rather than a metal.