What are permanent magnets made of?
Permanent magnets are made up of steels because magnetised steel does not lose its magnetism easily
What is a magnetic field?
The region around the magnet is called magnetic field. Any other magnetic material placed in this space experiences a force caused by the first magnet.
What is induced magnetism?
Induced magnetism is magnetism created in an unmagnetised magnetic material when the material is placed in magnetic field
What is a wire coiled into a spiral called?
A solenoid
How can you make the field around a solenoid stronger?
Increase the current
Add more turns to the coil
Add and iron core (making and Electromagnet)
What is an electromagnet?
An electromagnet is a solenoid in which the isolated wire is wrapped around an iron bar. When a current is passed along a wire. Because of this the magnetic fields of a wire magnetised the core (iron)
What is the equation which links force and magnetic flux density?
F = BXIXL
Force (N) = magnetic flux density (T) x Current (A) x Length (m)
What direction is the current at the south pole of a solenoid?
The south pole is the end where current is clockwise
What direction current at the north pole of a solenoid?
The north pole is the end where current is anticlockwise
Why does turning the turbine generate electricty?
The turbine causes the magnet inside the coil of wire (generator) to rotate. The moving magnet inside a solenoid induces potential difference in the wire
