lesson 2 - electromagnets Flashcards
1
Q
why does the iron core make the electromagnet stronger?
A
the domains in the iron line up with the field.
2
Q
which metal is the best to use as the core for an electromagnet?
A
iron because it loses magnetism when the current is switched off
3
Q
why are electromagnets used instead of ordinary bar magnets in scrapyards?
A
they can be turned off to release the scrap.
4
Q
one advantage of an electromagnet?
A
turn it on / off
5
Q
one disadvantage of an electromagnet?
A
needs a power supply
6
Q
why must the wire which is wrapped round the core of an electromagnet be insulated?
A
so it doesn’t get too hot.
