Magnetic field
The region in which a magnet or -carrying conductor can exert magnetic force. Drawn field lines show direction and give a visual guide to strength, but they are a model rather than physical wires. Changing magnetic flux through a coil can induce a , linking this idea to motors and .
Using Magnetic field in context
Updated
A distinction worth remembering
A field describes magnetic effects in a region. Field-line drawings show direction and relative pattern; the lines are a model, not physical threads inside a component.
Questions to take further
- How can I revise Magnetic field beyond the definition?
- Explain what Magnetic field describes, compare it with a related term and use it in a topic question. State any assumptions and what evidence you would need before applying the idea to real work.
Sources
- OpenStax University Physics: Magnetic fields produced by currents — The physical principle used in this comparison; technical installation requirements remain separate.
Where Magnetic field fits in the learning path
The Electrical Science section covers these units:
- Circuit Fundamentals
Curriculum mapping: C&G 2365 Units 202/302.
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- Ohm's LawElectrical Science
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Recall a related term
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The production of a voltage when the magnetic flux linking a conductor changes. Moving a conductor through a magnetic field or changing the field around a coil can cause it. This is the principle behind generators and transformers; the induced voltage depends on the rate of change, not simply on a magnet being present.
Electromagnetic induction
Read the Electromagnetic induction entryCompare related terms
Open a meaning to compare its role with Magnetic field, or follow its full entry.
Electromagnetic induction
The production of a voltage when the magnetic flux linking a conductor changes. Moving a conductor through a magnetic field or changing the field around a coil can cause it. This is the principle behind generators and transformers; the induced voltage depends on the rate of change, not simply on a magnet being present.
Read the Electromagnetic induction entryElectromagnet
A magnet whose field is produced by electric current, often using a coil and an iron core to concentrate the field. Its pull can be switched or changed by changing the current, which is why relays and contactors can use it. It differs from a permanent magnet that keeps its field without a supply.
Read the Electromagnet entryTransformer
A device that transfers electrical energy between windings through a changing magnetic field. It can raise or lower AC voltage according to the winding arrangement, with losses meaning output power is below input power. A site centre-tapped transformer also changes how its output is referenced to earth.
Read the Transformer entryA definition is a start. Using it in a real question is where it sticks.