| English | Induced current |
|---|---|
| Bahasa Melayu | Arus aruhan |
| 中文 | 感应电流 |
Definition
The current that flows in a closed conductor as a result of electromagnetic induction.
In exam terms
An induced current is the current that flows in a closed conductor as a result of electromagnetic induction. It is measured in amperes (A) and only exists while the magnetic field linking the circuit is changing and the circuit is complete.
The direction of an induced current is given by Lenz's law: it flows so as to oppose the change that produced it. The size increases with a faster rate of change of the field, more turns, and a stronger magnet.
Example of correct use: As the north pole of a magnet is pushed into the coil, the induced current flows so that the near face of the coil also becomes a north pole, repelling the magnet.
Do not confuse it with…
Do not confuse induced current with the induced e.m.f. The e.m.f. is the voltage produced by induction and can exist even in an open circuit; the induced current only flows when there is a complete circuit for it to move through. No closed loop means an e.m.f. but no current.
In Paper 2 this appears as state or explain: state the direction of the induced current, or explain how Lenz's law fixes that direction. Answer by naming Lenz's law and stating that the current opposes the change causing it.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)