magnetism Flashcards
(6 cards)
1
Q
what materials are magnetic
A
iron, nickel and cobalt
2
Q
what is an electromagnet
A
a coil wrapped around a metallic core. current is passed through the coil producing a magnetic field similar to that of a bar magnet
3
Q
what are the advantages of electromagnets
A
they can be turned on and off and the strength can be changed
4
Q
what are electromagnets used for
A
lifting cars, DC motors
5
Q
what can you do to increase the strength of an electromagnet
A
increase number of turns in coil, increase current, iron core
6
Q
what are relays and how are they used
A
relays are switches that open and close circuits electronically. they control one electrical circuit by opening and closing contacts in another circuit
