Physics 5054 · O Level · Electromagnetic induction
Electromagnetic induction — practice question
A student raises a metal bar upwards through the space between the poles of a magnet, as illustrated in Fig. 6.1.
Fig. 6.1 illustrates a metal bar moving upwards between the N and S poles of a magnet, with an ammeter connected.
As the bar moves, the connected ammeter shows a small positive reading.
(a)[2]
Explain why the ammeter gives a reading.
(b)[3]
Fill in Table 6.1 by stating the ammeter reading when the metal bar moves in the arrowed direction in each diagram.
(c)[1]
The student discovers that a stronger magnet gives a larger ammeter reading.
State one other way the student can make the ammeter reading larger, using the same rod.
(d)[1]
Describe how Lenz’s law works when the bar is moved upwards.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Bar cuts magnetic field lines or magnetic flux changes” …