Magnetism: Electromagnets (DONE) Flashcards
What is produced when a current flows through a wire?
A magnetic field is produced around a wire when a current flows through it.
How can we prove that there is a magnetic field around a wire?
We can prove that there is a magnetic field around a wire by using a compass because when the current is turned off, the compass needle lines up with the earths magnetic field but if we turn the current on then the compass needle will deflect.
What are the ways we can increase the strength of an electromagnet’s magnetic field?
List three (3)
We can increase the strength of an electromagnet by increasing the number of turns of the coil in our solenoid. More coil turns = stronger magnetic field around a wire.
We can increase the strength of the current that flows through the solenoid.
We can add an iron core to the inside of our solenoid since iron is a magnetic material this will cause it to become an induced magnet.
What happens to the direction of a magnetic field if we change the direction of a current
If we change the direction of a current then we change the direction of a magnetic field.
What must you do if you’re asked to work out the direction of the magnetic field produced by the wire?
The rule.
To work out the direction of the magnetic field produced by a wire we use the right hand grip rule.
What is the name given to a coiled wire?
A solenoid is the name given to a coiled wire.
What is the right hand grip rule for?
The right hand grip rule is to figure out either the direction of a current or magnetic field goes in.
The magnetic field is strongest closer to the wire.
What is the current like within a solenoid?
Within a solenoid the current is strong and uniform.
Why are electromagnets useful?
Electromagnets are useful as they can be turned on and off and we can change the strength of the magnetic field by controlling the size of the current.
