P4.1 - Magnetism Flashcards Preview

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Flashcards in P4.1 - Magnetism Deck (26)
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1
Q

what is used to model a magnetic field?

A

magnetic field lines

2
Q

what is the number of field lines passing through a particular area called?

A

magnetic flux density/ magnetic field strength

3
Q
A

.

4
Q

what does the density of field lines show?

A

the strength of the magnetic field

5
Q

give an example of an induced magnet

A

when a paperclip is attracted to a magnet

6
Q

why does steel not always have magnetic properties?

A

as its domains are not always lined up

7
Q

why does steel and iron become magnetic when in a magnetic field?

A

as it causes the domains to line up in the same direction (towards a pole)

8
Q

why do permanent magnets stay lined up when a magnetic field is removed, but (soft) magnetic materials do not?

A

as the domains continue to be lined up (permanent), but in a (soft) magnet, they revert back to their original direction

9
Q

where does a compass point?

A

magnetic north pole (which is geographical south pole)

10
Q

which way do field arrows point around a bar magnet?

A

north to south

11
Q

how can you work out the direction of a magnetic field around a current?

A

using the RIGHT hand rule

12
Q

if the current is coming towards you, which way would the field lines be going?

A

anti-clockwise

13
Q

What does the strength of the field around the wire depend on

A
  • magnitude of the current

- distance from the wire (closer to wire, stronger field)

14
Q

What is the strength of a magnetic field measured in (units)?

A

Teslas (T)

15
Q

what is the strength of the earth’s magnetic field?

A

0.01 mT

16
Q

What is a solenoid?

A

a coil of wire that carries a current

17
Q

how do you make fields of a solenoid stronger?

A

putting a magnetic material inside the core

18
Q

what does putting a magnetic material inside am solenoid produce?

A

an induced magnet

19
Q

what is magnetism?

A

the ability of magnets to attract and repel other magnetic without contact

20
Q

what are the only pure metals that can be turned into magnets (magnetic materials)?

A

iron, nickel, cobalt

21
Q
A

-

22
Q

what can magnets attract and repel?

A
  • they can attract and repel other magnets
23
Q

which kind of magnets produce a magnetic field?

A

only permanent magnets

24
Q

what is the difference between permanent and induced magnets?

A
  • permanent magnets are always magnetic, and always have poles
  • induced magnets are only magnetic when have a permanent magnet near them - do not always have poles
25
Q

how does the behaviour of a magnetic compass relate to evidence that the core of earth must be magnetic?

A
  • magnet points towards magnetic north pole
26
Q

what four factors affects the strength of the field produced on a solenoid?

A
  • size of current
  • distance from conductor
  • number of coils
  • type of core used