Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Science year 8 > P1 Electricity > Flashcards

P1 Electricity Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the two types of electric charges

A

Positive charge

Negative charge

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

What charges attract

A

Positive and negative (opposites)

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

What charges repel

A

The same:
Positive and positive
Negative and negative

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

What are charges

A

A property of a particle or object

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

What charge do protons have

A

Positive

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

What particle has a negative charge

A

Electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of charge do Neutrons have

A

None - it’s neutral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are particles

A

Smaller parts of atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many charges do atoms contain

A

An equal number of protons and electrons - over all an atom has no charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does a storm use Charge

A

The charges move around the cloud producing regions that have a + or - charge. Electrons jump from different charges areas and produces a big current.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an electric field

A

A region where a charged material or particle experiences force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where is an electric field

A

Around a charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a current

A

The amount of charge flowing per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the switch do

A

Opens and closes a gap in the circuit- you close the gap to complete the circuit and open it to cut the current off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you measure current

A

With an ammeter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What unit is current in

A

Amps (A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where do charges come from

A

The charges are already in the wires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do charges move around a circuit

A

The cell (battery) pushes it around the circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does a rope model show what happens in wire when current flows

A

One person pulls the rope and the other grips it lightly - the rope moves around.
The rope represents the charges in a circuit and the amount of rope moving past a point per sec is the charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is potential difference

A

The push provided by a cell or battery to make the charges move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the p.d. across a cell tell you

A

The size of the force on the charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do you measure potential difference

A

Using a voltmeter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The is the unit and measurement for p.d.

A

Volts (V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do you measure the p.d. Across a cell

A

Connecting the voltmeter across it - this is also called the rating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the current in a series circuit like

A

The same through out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the p.d. in a series circuit like

A

Shared between each components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the current in a parallel circuit like

A

The ammeter measuring the battery is the sum of the other ammeters measuring other components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the p.d. in a parallel circuit like

A

The voltage is the same in each branch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the two types of circuits

A

Series and Parallel

30
Q

What are the factors of a series circuit

A

All the bulbs are formed on one loop (old Christmas lights)

31
Q

What is the main factor of a parallel circuit

A

More that one loop (branch)

32
Q

What’s the benefit of a parallel circuit

A

If one bulb breaks all the others stay on

33
Q

What is the current like in a series circuit

A

The current is the same everywhere. If you add components then the current will get smaller

34
Q

What is the current like in a parallel circuit

A

The currents in all the branches of the circuit add together to make the total current. If you add another branch the total current increases and the other branches stay the same

35
Q

How would you use a rope model to show a series circuit

A

The rope would move the same speed everywhere and as the more people hold the rope the slower the rope moves

36
Q

How would you use the rope model to show a parallel circuit

A

There would be more loops of rope and all the loops are driven by the same ‘battery’ person

37
Q

What does the resistance in a component tell us

A

How easy or difficult it is for charges to pass through the component

38
Q

What is the unit for resistance

A

Ohms (Ω)

39
Q

What does the current depend on

A

The push of the battery and the resistance of the component

40
Q

How do you calculate the current

A

Current(A) = potential difference(V) .\’ resistance(Ω)

41
Q

How can you use resistance

A

To explain why the current decreases as you add more bulbs in a series circuit (adding more bulbs increases the resistance so the current is less)

42
Q

How do you calculate resistance

A

Resistance(Ω) = p.d. (V) .\’ current (A)

43
Q

How do you model resistance

A

Using marbles - if you had a slop (at the top marbles and on the ramp posts) as the marbles fall down they act like electrons and the posts represent resistance

44
Q

What is a conducter

A

A material that conducts charge or energy well, such as a metal or graphite

45
Q

What makes metals good conductors

A

Because they have very low resistance as they contain lots of electrons that can move the resistance of a 10m piece of copper wire is 0.2Ω

46
Q

Why are plastics such bad conductors

A

Because they don’t have as many electrons that are free to move. The resistance of plastic objects is very high (over a thousand million million ohms)

47
Q

What are insulators

A

A material that does not conduct electrical or transfer energy well

48
Q

Which poles of the magnet repel

A

The same ones -
North and north
South and south

49
Q

Which of the poles on a magnet attract

A

Opposite-

North and south

50
Q

What are the materials that are attracted to magnets called

A

Magnetic materials (iron, nickel, cobalt)

51
Q

What is an electric field

A

Where there is force on a charge

52
Q

What is a magnetic field

A

When there is force on a magnet or a magnetic material

53
Q

How do you find out the shape of a magnetic field

A

Using plotting compasses or iron filings

54
Q

What are the lines called that represents the magnetic field

A

Magnetic field lines

55
Q

What does it mean if the field line are closer

A

The magnetic field is stronger

56
Q

What is a permanent magnet

A

A magnet that has its own magnetic field

57
Q

Why would a magnet line up with north and south if you hang it

A

Because of the Earths magnetic field

58
Q

What is an electromagnet

A

A temporary magnet produced using an electric current

59
Q

How do you make an electromagnet

A

Make a circular loop of wire and pass a current through it - the magnetic field lines are straight at the centre of the loop. A singular loop isn’t very strong so if you put lots of loops together the field is a lot stronger.

60
Q

How do you turn an electromagnet on and off

A

By turning the current on and off - the magnet only works with current running through the wire

61
Q

What is a core

A

The magnetic material in the centre of the coil - this makes the electromagnet much stronger

62
Q

What are most cores made of

A

Iron because it is easy to magnetise but it loses its magnetism easily

63
Q

What would be a good material to make a coil out of if you wanted it to stay magnetic when off

A

Steel

64
Q

How do you make an electromagnet stronger

A

Add more turns or loop on the coil
Add more current flowing through the wire
The type of core it has

65
Q

What is the main differences between permanent magnets and electromagnets

A

You can turn an electromagnet on and off

You can make electromagnets much stronger than permanent magnets

66
Q

How do trains use electromagnets

A

Beginners use magnets repelling to build trains use if magnetic levitation - the train is lifted by magnets.
Powerful electromagnets on the track repel magnets on the train - there is no friction so it can go faster

67
Q

What is relay

A

Electrical device that uses current flowing through it in one circuit to switch on and off a current in a second circuit

68
Q

Why can X-Rays be dangerous

A

That have a very high Potential difference

69
Q

How does a relay work

A

A relay uses a small current in a circuit to operate a switch on another. When the switch is closed the coil becomes an electromagnet- the two pieces of iron inside are magnetised they attract each other an turn on the second circuit

70
Q

How can you use an electromagnet magnet to sort metal

A

Iron and steel will be attracted to it but other metals like aluminium won’t

71
Q

What is a motor

A

A component or machine that spins when a current flows through it

72
Q

How do you make a simple motor

A

Using two magnets and a coil of wire.
Connect the coil to a battery allows a current to flow in the coil - it’s now an electromagnet. The forces between the coil and permanent magnet makes the coil spin

Science year 8 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions