Question 22M.2.HL.TZ2.b.i
| Date | May 2022 | Marks available | [Maximum mark: 3] | Reference code | 22M.2.HL.TZ2.b.i |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | b.i | Adapted from | N/A |
A fixed horizontal coil is connected to an ideal voltmeter. A bar magnet is released from rest so that it falls vertically through the coil along the central axis of the coil.
The variation with time t of the emf induced in the coil is shown.
Explain why the graph becomes negative.
[3]
ALTERNATIVE 1
Flux linkage is represented by magnetic field lines through the coil ✓
when magnet has passed through the coil / is moving away ✓
flux «linkage» is decreasing ✓
suitable comment that it is the opposite when above ✓
when the magnet goes through the midpoint the induced emf is zero ✓
ALTERNATIVE 2
reference to / states Lenz’s law ✓
when magnet has passed through the coil / is moving away ✓
«coil attracts outgoing S pole so» induced field is downwards ✓
before «coil repels incoming N pole so» induced field is upwards
OR
induced field has reversed ✓
when the magnet goes through the midpoint the induced emf is zero ✓
OWTTE
