Physics 9702 · AS & A Level · Force on a moving charge
Force on a moving charge — practice question
Fig. 6.1 shows a narrow sheet of semiconducting material in a Hall probe. Current $I$ flows through the slice in the direction indicated. The slice is placed in a uniform magnetic field with flux density $B$, arranged so that two of its faces are at right angles to the magnetic field. A constant Hall voltage $V_H$ is produced between face $PQXW$ and face $SRYZ$.
(a(i))[1]
Use the letters in Fig. 6.1 to pick out the faces that lie at right angles to the magnetic field.
(a(ii))[3]
Explain how the steady Hall voltage $V_H$ is formed between faces $PQXW$ and $SRYZ$.
(b(i))[3]
The size of $V_H$ is given by the equation $V_H = \frac{BI}{ntq}$. State what the symbols $n$, $t$ and $q$ mean. You may use the letters in Fig. 6.1.
(b(ii))[2]
Suggest, with reference to the equation $V_H = \frac{BI}{ntq}$, why the material slice in a Hall probe is thin.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “PQRS and WXYZ ” …