Magnetism and Electromagnetism Flashcards
What is a permanent magnet?
Produces its own magnetic field.
What is meant by “magnetic field”?
The region whee other magnets or magnetic materials experience a force.
What is an induced magnet?
A magnetic material that turns into a magnet when its put in a magnetic field.
What are the four magnetic materials?
> iron.
steel.
nickel.
cobalt.
What is an electromagnet?
A solenoid with an iron core. It is a magnet that can be turned on and off.
What is the motor effect?
When a magnet and a current-carrying conductor exert a force on each other.
What are the three ways of increasing the force?
> increase the current.
increase the magnetic field strength.
increase the length of the conductor.
What is a solenoid?
A coil of wire.
How can you increase the strength of the magnetic field that a wire produces?
By wrapping the wire into a coil called a solenoid.
How is the magnetic field inside a solenoid?
> strong.
uniform.
has the same strength and direction at every point in its region.
How can you increase the field strength of a solenoid?
Putting block of iron in the centre of the coil as the iron core becomes an induced magnet whenever current is flowing.
What happens to the magnetic field if the current stops?
It disappears.
What three things does the force acting on a conductor in a magnetic force depend on?
> the magnetic flux density which shows the strength of the magnetic field.
the size of the current through the conductor.
the length of the conductor thats in the magnetic field.
How does the force on a conductor in a magnetic field cause the rotation of the coil in an electric motor?
As the coil is on an axle and the forces act one up and one down, it rotates.
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