P5: Electricity In The Home Flashcards
What does AC mean for a circuit?
The circuit has alternating current
What does DC mean for a circuit?
The circuit has direct current
What is an alternating current?
When the current in a circuit is constantly changing direction
What is a direct current?
When the current in a circuit does not change direction at all and is constantly flowing in a single direction
What does the ‘mains electricity’ refer to?
It refers to the electricity supplied to homes and businesses from power stations
What is the frequency and voltage of the ‘mains electricity’?
- 230V
- 50Hz
What does it mean if an alternating current is at 50Hz?
It means the current flow changes direction and back 50 times per second
Why are transformers an essential part of the national grid’s distribution system?
As step-up transformers can increase the voltage (and decrease the current) when passing the electricity onto transmission cables,
and step-down transformers can decrease the voltage (and increase the current) when passing electricity onto our homes.
Why do most cables have plastic or rubber casing?
As plastic and rubber are extremely poor electrical conductors so they will not transfer the electricity from the wires to the outside world
What are the 3 wires of a plug?
- Earth wire
- Neutral wire
- Live wire
What colour is the earth wire?
Green and yellow
What colour is the neutral wire?
Blue
What colour is the live wire?
Brown
What does the live wire (brown wire) do?
Carries current to the appliance at a high voltage
What does the neutral wire (blue wire) do?
Completes the circuit and carries current away from the appliance
What does the earth wire (green and yellow wire) do?
It is a safety feature and connects the metal case of an appliance to the earth to stop the appliance becoming live
What is a 3-core cable and when would a 3-core cable by neccesary?
It is a wire which has all 3 wires (neutral wire, live wire and earth wire),
it is necessary when the appliance it is plugging in to has a metal case.
What is a 2-core cable and when would a 2-core cable by neccesary?
It is a cable that does not have an earth wire (only live and neutral wire),
it is necessary when the appliance it is plugging in to does not have a metal case (usually has a plastic case)
What is electrical power?
The rate of energy transfer by each electrical component
What is the equation for electrical power?
Electrical Power = Energy / Time
What are the 4 different fuses?
- 1A fuse
- 3A fuse
- 5A fuse
- 13A fuse
What is a fuse?
A fuse is a part of a circuit that melts and breaks the circuit if the current reaches too high of a level
Which fuse should you always pick relative to the current of the circuit?
You should always pick the next fuse up from the current of the circuit
E.g if the circuit has a current of 3.5A, you should use the 5A fuse
What is charge flow in a circuit?
When electrons are forced through components by the potential difference of the battery/cell in the circuit
