Electromagnetism
- Created by: Megannia2000
- Created on: 12-04-17 10:10
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- Magnetism
- Magnetic Fields
- All currents have a magnetic field around them.
- As you move away from a wire the magnetic field gets stronger, this is why the lines are drawn further apart.
- Electro-magnets
- Temporary Magnets
- These are far more useful than permanent magnets because:
- They can be switched on and off
- The strength of the magnetic field can be changed by altering the current
- They can easily be made into a variety of shapes and are less expensive to make
- The magnetic field around a coil electro-magnet can be increased by:
- Increasing the current in the wire
- Putting more loops on the coil
- Placing an iron or steel core inside a coil
- Iron-magnetically soft
- easy to magnetise
- loses its magnetism quickly when current is switched off
- most electro-magnetic devices use iron as the core as they want the magnetism to change quickly
- Steel-magnetically hard
- harder to magnetise
- stays magnetic after current is switched off
- Iron-magnetically soft
- Motor Effect
- When two magnets are together they affect each other and produce a force (this also happens when two magnetic fields are close together)
- If a wire carrying a current is placed on a magnetic field a force is produced, called the motor effect
- the direction of the force will depend on the direction of the magnetic field and direction of current in the field
- FLEMMING'SLEFT HAND RULE
- the direction of the force will depend on the direction of the magnetic field and direction of current in the field
- If a wire carrying a current is placed on a magnetic field a force is produced, called the motor effect
- Magnetism
- Magnetic Fields
- All currents have a magnetic field around them.
- As you move away from a wire the magnetic field gets stronger, this is why the lines are drawn further apart.
- Electro-magnets
- Temporary Magnets
- These are far more useful than permanent magnets because:
- They can be switched on and off
- The strength of the magnetic field can be changed by altering the current
- They can easily be made into a variety of shapes and are less expensive to make
- The magnetic field around a coil electro-magnet can be increased by:
- Increasing the current in the wire
- Putting more loops on the coil
- Placing an iron or steel core inside a coil
- Iron-magnetically soft
- easy to magnetise
- loses its magnetism quickly when current is switched off
- most electro-magnetic devices use iron as the core as they want the magnetism to change quickly
- Steel-magnetically hard
- harder to magnetise
- stays magnetic after current is switched off
- Iron-magnetically soft
- Motor Effect
- When two magnets are together they affect each other and produce a force (this also happens when two magnetic fields are close together)
- If a wire carrying a current is placed on a magnetic field a force is produced, called the motor effect
- the direction of the force will depend on the direction of the magnetic field and direction of current in the field
- FLEMMING'SLEFT HAND RULE
- the direction of the force will depend on the direction of the magnetic field and direction of current in the field
- If a wire carrying a current is placed on a magnetic field a force is produced, called the motor effect
- When two magnets are together they affect each other and produce a force (this also happens when two magnetic fields are close together)
- Magnetic Fields
- When two magnets are together they affect each other and produce a force (this also happens when two magnetic fields are close together)
- Magnetic Fields
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