Explain why, as the Hall probe is turned around the horizontal axis XY, the Hall voltage changes from a maximum positive value to a maximum negative value.
The maximum Hall voltage $V_H$ is recorded at several different distances $r$. The values of $V_H$ and the matching values of $r$ are given in Fig. 5.2. It is suggested that $V_H$ and $r$ are linked by an equation of the form $V_H = \frac{k}{r}$, where $k$ is constant.
Without plotting a graph, use the data in Fig. 5.2 to decide whether the expression $V_H = \frac{k}{r}$ is valid.
A graph of $V_H$ against $\frac{1}{r}$ is drawn. State the graph features that indicate that the expression $V_H = \frac{k}{r}$ is valid.
State Faraday’s law of electromagnetic induction and hence explain why the voltmeter shows a zero reading.
State three different methods by which an e.m.f. may be induced in the coil.