Brainscape's Knowledge GenomeTM

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


See full index

Physics GCSE > P5. Electricity in the home > Flashcards

P5. Electricity in the home 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

Is mains electricty an a.c supply or d.c supply? What do each of these stand for

A

Mains electricity is an a.c supply

a.c. : Alternating current

d.c. : Direct current

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

Define alternating current and direct current

A

Alternating current: Current that continuously changes direction at a specific frequency
Direct current: One directional current flow

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

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

A

Frequency: 50 Hz
Voltage: 230V

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

How many wires are usually in the cables connecting electrical appliances to the mains? Name these wires

A
  1. Live wire
  2. Neutral wire
  3. Earth wire
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

State the insulation colour used on the Earth wire.

A

Green and yellow stripes

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

State the insulation colour used on the live wire.

A

Brown

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

State the insulation colour used on the neutral wire

A

Blue

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

Explain when the Earth wire does and doesn’t carry a current.

A

Under normal circumstances, no current flow through the Earth wire
If a fault occurs in the appliance (such as the surge or the casing becoming live), current will flow to the ground

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

What potential is the neutral wire at?

A

0 volts

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

State the potential difference between the live and earth wires.

A

230 volts

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

What is the purpose of the neutral wire?

A

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

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

For metal appliances, where is the Earth wire connected to? Why?

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

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

State two equations for the power of a circuit. Give appropriate units

A

P = I V P = I² R

Power (Watts) = Current (Amperes) x Potential difference (volts)
Power (Watts) = Current² (Amperes) x Resistance (Ohms)

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

State an equation linking energy transferred, power and time. Give appropriate units

A

E = P t

Energy (Joules) = Power (Watts) × Time (Seconds)

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

State an equation linking energy transferred, power and time. Give appropriate units

A

E = Q V

Energy (Joules) = Charge (Coulombs) × Potential Difference (Volts)

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

What two main factors does the amount of energy transferred by an appliance depend on?

A
  1. How long the appliance is being used for
  2. The power of the appliance
17
Q

Describe the energy transfers in a battery powered torch.

A

Battery converts chemical energy into electrical energy
Bulb converts electrical energy into light as well as waste energy in the form of heating

18
Q

Describe the energy transfers in a battery powered motor

A

Battery converts chemical energy into electrical energy
Motor converts electrical energy into kinetic energy as well as waste energy in the form of heating due to friction

19
Q

What three things determine the power of a circuit device?

A
  1. The potential difference across the circuit
  2. The current through the circuit
  3. The amount of energy transferred in a given time
20
Q

What is the purpose of the National Grid?

A

To link power stations to consumers so that they have access to a source of electricity

21
Q

What are two types of transformers used in the National Grid?

A
  1. Step-Up Transformers
  2. Step-Down Transformers
22
Q

Where are step-up transformers found in the National Grid? What do they do?

A

Step-Up Transformers are used when connecting power stations to transmission cables
They increase the potential difference

23
Q

What are step-down transformers found in the National Grid? What do they do?

A

Step-Down Transformers are used in connecting transmission cables to domestic buildings (like houses)
They decrease the potential difference

24
Q

Why do transmission limes transfer electricity at high potentials?

A

A high potential, results in a low current
The lower the current, the less energy that is wasted as heat
Therefore it is more efficient

25
Q

Why does the potential need to be decreased between transmission lines and houses?

A

Lower potentials are safer for domestic use and reduces the likelihood of severe electrocution
Appliances are designed for 230V

26
Q

What can happen when insulating materials are rubbed together?

A

They can become (statically) electrically charged

27
Q

Why can insulators become electrically charged when rubbed together?

A

Electrons are rubbed from one material onto the other
The material gaining electrons becomes negatively charged
The material losing electrons becomes equally positively charged

28
Q

What happens when two electrically charged objects are brought close together?

A

They exert a force on each other

29
Q

What happens when two identically charged objects are brought close together?

A

They exert a repulsive force on each other and repel

30
Q

What happens when two oppositely charged objects are brought close together?

A

They exert an attractive force on each other and attract

31
Q

Give an example of a non-contact force

A

The repulsive or attractive force acting between two electrically charged objects

32
Q

What is an electric field?

A

A region in which a charged object will experience a non-contact electrical force

33
Q

Where can electric fields be found?

A

Surrounding any charged object

34
Q

Describe the electric field around a charged particle.

A

Strongest closest to the object
Decreases in strength as you move away from the object

35
Q

What happens to the force between two charged objects when they are moved closer together?

A

The forces between them becomes stronger as the separation reduces

36
Q

In situations where sparks are unwanted, what precaution must be taken to prevent the build up of static charge?

A

Any surfaces that are rubbing against each other should be earthed to allow the charge to flow off the materials.

Physics GCSE (11 decks)

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