Brainscape's Knowledge GenomeTM

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


See full index

AQA GCSE Physics > P2 (Electricity) > Flashcards

P2 (Electricity) Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards GCSE Religious Studies - Edexcel Route A flashcards AP® Physics flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Geography - AQA flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What is electric current?

A

The flow of electrical charge.

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

What is the equation for electrical charge?

A

Q=It

Charge = current x time

charge (coulombs), current (amperes), time (seconds)

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

What is the value of current at any point in a series circuit?

A

Current is the same at all points in a series circuit.

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

What two factors does the current in a circuit depend on?

A

Potential difference, resistance.

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

What is the equation for potential difference?

A

V=IR

Potential difference = current x resistance

potential difference (V), current (A), resistance (Ω)

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

What is an Ohmic conductor?

A
  • A conductor for which current and potential difference and directly proportional.
  • Resistance remains constant as current changes.
  • Temperature must be constant.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are four components for which resistance is not constant as current changes?

A

Lamps, diodes, thermistors, light dependent resistors (LDR).

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

What happens to the resistance of a filament lamps as the temperature increases?

A
  • Resistance increases.
  • Ions in metal have more energy, so vibrate more, causing more collisions with electrons as they flow through the metal, creating greater resistance to current flow.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the current flow in a diode?

A
  • The current only flows in one direction.

- Resistance is very high in the other direction, preventing current flow.

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

What happens to resistance of a thermistor as temperature increases?

A

The thermistors resistance increases.

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

When might a thermistor be used?

A
  1. In a thermostat to turn a heater on below a certain temperature.
  2. In a freezer to turn on a cooler when the temperature becomes too high.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens to the resistance of a LDR as light intensity decreases?

A

The LDR’s resistance increases.

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

When might an LDR be used?

A
  • Street lights often use LDRs.

- When light levels become too low, the light gains sufficient current to turn on.

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

What is a series circuit?

A

Series circuit is one loop; all electrons in that loop form one current.

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

What is a parallel circuit?

A

In a parallel circuit, electrical components are connected along side one another, forming extra loops.

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

Describe the potential difference in a series circuit?

A

Potential difference is shared between each component.

17
Q

Describe the potential difference in a parallel circuit?

A

Potential difference across each component is the same.

18
Q

Describe the resistance in a parallel circuit?

A

The total resistance is less than the smallest of the two individual resistance.

19
Q

Describe the resistance in a series circuit?

A

The total combined resistance is equal to the sum of the two individual resistances.

20
Q

Describe the current in a series circuit?

A

In a series circuit, the current is the same e at all positions since the charge only has one path to flow through.

21
Q

Describe the current in a parallel circuit?

A

In a parallel circuit, the current is shared between the different branches. When the charge reaches a junction, it splits.

22
Q

How should you connect an ammeter in a circuit to measure current?

A

Ammeters should be connected with component that they are measuring current through.

23
Q

How should voltmeters be connected in a circuit?

A

Voltmeters should be connected in parallel to the component that they are measuring the potential difference of.

24
Q

Why is it better to connect lamps in parallel?

A

If one lap blows, the rest will be unaffected and can still receive current (i.e the circuit is still complete)

25
Q

What does a.c stand for?

A

Alternating current

26
Q

What does d.c stand for?

A

Direct current?

27
Q

What type of electricity supply does mains electricity use?

A

a.c supply

28
Q

What is alternating current?

A

Current that continuously changes direction at a specific frequency.

29
Q

What is direct current?

A

One directional current flow.

30
Q

What is the frequency and voltage of the UK mains electricity supply?

A

Frequency: 50Hz
Voltage: 230V

31
Q

What are three wires connected in the cables connecting electrical appliances to the mains?

A

Live wire, neutral wire, earth wire.

32
Q

Describe the insulation colour used on the earth wire?

A

Green and yellow stripes.

33
Q

Describe the insulation colour used on the live wire?

A

Brown.

34
Q

Describe the insulation colour used on the neutral wire?

A

Blue.

35
Q

What is the purpose of the earth wire?

A
  • Under normal circumstances, no current flows through earth wire.
  • If a fault occurs in the appliance (such as a surge or the casing become live), current will flow to the current.
36
Q

What is the potential difference of the neutral wire?

A

0 volts.

37
Q

What is the potential difference between the live and earth wires?

A

230 Volts.

38
Q

What is the purpose of the neutral wire?

A

To complete the circuit by connecting the appliance back to the mains supply.

39
Q

For metal appliances, where is the earth wire connected to?

A
  • Earth wire is connected to the metal casing of the appliance.
  • If live wire becomes loose and touches the casing, the current will flow through the earth wire, preventing electrocution.

AQA GCSE Physics (2 decks)

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