E Magnetism Flashcards
1
Q
What is a relay?
A
A small voltage/current is used to close a contact controlling a larger voltage/current
2
Q
What is a solenoid?
A
A moving magnetic core on a spring within a coil
3
Q
How does a solenoid work?
A
When switched on the metal core is attracted into the field and compresses the spring, when switched off the spring returns the core to its original position
4
Q
What is faradays law?
A
E = N x dB or E = N x dt
E - EMF, N- number of turns in the wire, dB - change in field strength, dt - change in time
5
Q
What are the 2 types of magnets?
A
- Permanent magnets
2. Electromagnets
