Supplying electricity Flashcards
A cell or battery provides what sort of current?
Direct Current (DC)
What type of electricity does mains provide?
Alternating current (AC)
What does the current do in a Alternating Current (AC)?
The current repeatedly reverses direction and is produced by an alternating potential difference.
What do the positive and negative of an alternating power supply do?
Swap over with a regular frequency.
What is the Frequency of the mains electricity in the UK?
50 Hz
What is the Voltage of the mains electricity in the UK?
230 V
Why is the earth wire included?
To stop the appliance becoming live. The potential difference of the wire is normally 0V.
What does the Neutral current do?
The neutral wire completes the circuit. It has a potential difference of 0V.
Why is plastic used as the wire coatings?
Because Plastic is a good insulator.
Why is the live wire dangerous?
It carries a Potential difference of 230V.
What happens to the fuse when the Live wire connects to the neutral wire?
A very large current flows. This is called a short circuit, when this happens the fuse melts and disconnects the live wire.
What is the national grid?
The national gird is a nationwide network of cables and transformers that link power stations to homes, offices, and other consumers of mains electricity.
What is a transformer?
Transformers are devices that can change the potential difference of an alternating current.
What potential difference is generated at a power station?
25000 V
How much is transferred along the cables in the national grid?
4000000 V
