- an electric current in a material produces a magnetic field around it
- the larger the electric current, the stronger the magnetic field
- the direction of the magnetic field depends on the direction of the current
Paper Two-
Straight wire, Flat circular coil and Solenoid:
The magnetic field around a straight wire is circular:
The magnetic field around a flat circular coil ellipses (egg-shaped):
The magnetic field around a solenoid is electromagnet:
If something with a charge is moving across a magnetic field it will
experience a force from the field, unless it's parallel.
D.C. Electric Motor (simple):
- wire in magnetic field
- force turns a 'split ring communicator' ---> charge goes from brushes in wires
Four factors
- more current
- more turns on coil
- stronger magnetic field
- soft iron core
Loudspeaker:
- force pushes current away from field, pushes core which makes sound ---> cone vibrates
The left hand rule:
Helps to figure out the thrust/motion, field and current of the wire to then work out which way the force is acting.
Wire in magnetic field increase (<) current = more force on wire
Wire in magnetic field increase (<) strength = more force on wire