Electromagnetism Flashcards
1
Q
What happens if you run an electric current through anything that conducts ?
A
A magnetic field will be produced around it
2
Q
Describe the construction of electromagnetics
A
- a piece of wire is wrapped around a soft magnetic material
- when there is a current in the wire a magnetic field is induced in the metal
3
Q
Magnetic field lines around a long wire
A
Screw driver rule - if the wire is facing downwards the lines go clockwise and if the wire is facing upwards the lines go anti-clockwise
4
Q
Magnetic field lines around a loop of wire
A
- closer to the wire is more circular field lines
* further away eg. Middle of the wire, the flatter the field lines
5
Q
Magnetic field lines through s solenoid
A
Solenoid has the same field lines shape as a bar magnet
6
Q
What is Flemings left hand rule
A
- thumb - movement of wire
- index - from bottom N to S is the field finger
- middle finger - from bottom + to - is the current finger
