Electricity in the home Flashcards
What is a direct current
A Direct current D.C always flows in one direction but can change in size.
What does a Direct current look like
Draw it:
What is an alternating current
An alternating current A.C changes direction back and forth
What does an Alternating current look like
Draw it:
What is in a plug
- 3 wires
- flex cable
- Fuse
- Cable grip
What are the three wires in a plug and their colours
- Earth wire- Green/yellow, Middle
- Live wire- Brown, Right
- Neutral- Blue, Left
What is the Earth wires use
When connected to an appliance if there is a fault, itll provide a low resistance path for the current to travel through, protecting the user.
What is the Live wires use
It pushes current around the circuit
What is the Neutral wires use
Provides a path for the current to travel through in normal operation.
How does a fuse protect a user
- Fuses are used when an appliance has a metal casing.
- if the live wire comes loose and touches the casing it can provide risk to the user.
- The current now travels through the live and earth wire, the total resistance has dropped therefore the current has increased.
- This causes the wires in the fuse to heat up and break
- This causes the circuit to break not allowing current to flow
- Protecting user from potential electrocution.
What is a fuse
It is an electrical component that consists of a thin piece of metal wire. Each wire is designed for a specific thickness so that when the current exceeds a certain value eg: 2A the wire heats up and breaks eg: Blowing a fuse.
What is the equation used for fuse questions
P=IV
P= Power in Watts
I= Current in Amps
V= Voltage in volts
What happens if a larger fuse thats not needed is used
The fuse may not blow and could cause electric shock or damage appliance
Where should a fuse and switch be placed
They must be placed between the live terminal and the user.
Draw where the fuse and switch should be placed in a circuit
Draw:
