6 MAGNETISM + ELECTROMAGNETISM Flashcards
What do magnetics do to magnetic substances
Attract them
Attraction of like poles
Repel
Attraction of unlike poles
Attract
Where do magnetic field lines run
North to South
Define a magentic field line
The direction of force on a small NorthPole at that point
What is a magnetically soft material
A material that gains and looses magnetism easily
How to draw uniform magnetic field lines
- Straight and with arrows from N -> S
- Close together = stronger force
What is a neutral point of a N-N magnet
- In the centre between field lines, where there is no magnetic field
- Magnetic forces balance (cancel)
How to investigate magnetism with iron filings
- Place magnet on desk, then paper over, and around with pencil marking north pole
- Carefully sprinkle iron filings on top
- Tap the paper to allow them to fall into place
How to investigate magnetism with plotting compasss
- Place magnet on piece of paper and draw around in pencil and mark north pole
- Place plotting paper on compasss
- Draw around plotting compass, and mark direction of arround with ‘x’
- Move plotting compass, so tail of arrow is on ‘x’ and mark direction again
- Repeat to build up field pattern
Unit for current
Ampere (A)
Unit for power
Watt (W)
Unit for voltage
Volt (V)
What happens when an electrical current flows through a conductor
It produces a magentic field around it
How do you increase the strength of an electromagnet
- Add a soft iron core
- Increase the current
- Add more coils