Each electron has charge $-q$ and drift speed $v$ in the slice. State the magnitude and the direction of the force exerted by the magnetic field on each electron as it enters the slice.
The force on the electrons creates a voltage $V_H$ across the semiconductor slice, with $V_H = \frac{BI}{ntq}$ where $I$ is the current in the slice. State the two faces between which the voltage $V_H$ is produced.
Use the letters in Fig. 8.1 to identify the distance $t$.
Aluminium $\left(^{27}_{13}\text{Al}\right)$ has a density of $2.7\,\text{g cm}^{-3}$. Assume that each aluminium atom provides one free electron to carry charge. Show that the number of charge carriers per unit volume in aluminium is $6.0 \times 10^{28}\,\text{m}^{-3}$.
A piece of aluminium foil is $0.090\,\text{mm}$ thick. The current in the foil is $4.6\,\text{A}$. A uniform magnetic field with flux density $0.15\,\text{T}$ acts at right angles to the foil. Use the value in (i) to calculate the voltage $V_H$ produced.