# Topic 7-Magnestism and electromagnetism Flashcards Preview

## Physics Gcse AQA 9-1 > Topic 7-Magnestism and electromagnetism > Flashcards

Flashcards in Topic 7-Magnestism and electromagnetism Deck (31)
1
Q

What are the two poles?

A

North and south.

2
Q

What do all magnets produce?

A

A magnetic field.

3
Q

Where is the magnetic field strongest on a magnet?

A

At the poles.

4
Q

The closer magnetic field lines are …

A

The stronger the magnetic field.

5
Q

Which direction do magnetic field lines always go?

A

From north to south.

6
Q

What forces can magnets experience?

A

Attraction or repulsion.

7
Q

North and a North?

A

Repulsion.

8
Q

South and a North?

A

Attraction.

9
Q

What device shows the direction of magnetic field lines?

A

A compass.

10
Q

What are the two types of magnets?

A

Permanent and induced.

11
Q

What is a permanent magnet?

A

A magnet that can produce its own magnetic field.

12
Q

What are induced magnets?

A

Magnetic materials that turn into a magnet when they are put into a magnetic field.

13
Q

What is the force between permanent and induced magnets?

A

Attraction.

14
Q

What happens when a current flows through a wire?

A

A magnetic field is created around the wire.

15
Q

How can you increase the strength of the magnetic field that a wire produces?

A

By wrapping the wire into a coil.

16
Q

What is the coil called that you wrap around a wire to increase the magnetic field?

A

A solenoid.

17
Q

What is a solenoid with an iron core called?

A

An electromagnet.

18
Q

What can electromagnets be used for?

A

To pick stuff up with a crane.

19
Q

What is the equation for force?

A

Magnetic flux density x current x length.

20
Q

What is the generator effect?

A

The induction of a potential difference in a wire which is moving relative to a magnetic field, or experiencing a change in magnetic field.

21
Q

What does the generator effect create?

A

A potential difference in a conductor.

22
Q

If the conductor is part of a circuit what does the generator effect create?

A

A current.

23
Q

what do dynamos generate?

A

A direct current.

24
Q

What do alternators generate?

A

An alternating current.

25
Q

How do microphones work?

A

By generating a current from sound waves.

26
Q

What type of current do transformers only work with?

A

An alternating current.

27
Q

What two types of coil do transformers have?

A

Primary and secondary.

28
Q

What are the two coils joined together with in a transformer?

A

An iron core.

29
Q

What are the two types of transformers?

A

Step up transformers and step down transformers.

30
Q

What do step up transformers have to increase the potential difference?

A

More turns on the secondary coil than the primary coil.

31
Q

What do step down transformers have to decrease the potential difference?

A

More turns on the primary coil than the secondary coil.