Electromagnetism Key Sentences Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What does a magnetic field line show?

A

A magnetic field line shows the direction of ‘free’ North Pole a compass would point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 key sentences for motor

A
  • current goes around the coil
  • if a current goes through a wire in a magnetic field it feels a force.
  • one side of the coil the force is up and it is down on the other side: therefore the coil rotates.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do you find out the direction of force (on a motor)?

A

Direction of force can be understood with the left hand rule.

First finger- field
Second finger-current
Thumb-force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Loudspeaker key sentences

A
  • When a current flows through the coil it creates a magnetic field.
  • The magnetic field in the coil either attracts it repels the permanent magnet.
  • The coil moves in and out and makes the diaphragm vibrate.
  • The vibration in the diaphragm makes the air vibrate which creates sound.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Key sentence for electromagnetic induction

A

If a wire experiences a change in magnetic field a current is induced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Key sentences for a generator

A
  • If a wire experiences a change in magnetic field a current is induced.
  • If the coil is rotated in a magnetic field a current is induced.
  • The output current is an alternating current.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Key sentences for transformers

A
  • If a current passes through a wire a magnetic field is formed.
  • If an a.c current is passed through the primary coil a changing magnetic field is induced.
  • The iron coil strengths the magnetic field.
  • A secondary coil experiences a changing magnetic field so a current is induced.
  • Transformers can be used to step-up or step-down the voltage.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Key sentences for motor effect

A
  • When a current lasses through a wire in a magnetic field e.g loudspeaker
  • If a current passes though a wire in a magnetic field is formed around the wire.
  • If a current carrying a wire is placed at 90 degrees to a magnetic field it feels a force.
  • You can calculate the direction of the force by using the left hand rule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly