P5- Mains electricity Flashcards
When does electricity demand peak?
Late in the afternoon
The formula for electric power is?
Power= voltage x current
What are step up transformers?
Increases the voltage and decreases the current.
What are step down transformers?
Decreases the voltage and increases the current
How does electric power enter our homes?
- Electric power is generated at a power station
2.Step up transformers increase the voltage but decrease current. - The electric power is transmitted via the national grid at low current which minimizes power loss.
- Step down transformers decrease the voltage and increase the current.
- Electric power is wired into our homes at a voltage that is relatively safe to use.
What is the max value of mains voltage?
230V
What is a furnace?
Part of a power station where fossil fuels are burnt to heat water.
What is a Turbine
Part of a power station. The high pressure steam is forced through a turbine, making it turn.
What is a generator?
In a power station, the turbine is attached to a generator which turns to generate electricity at a voltage of around 25000v
What is the national grid network?
Electricity that is transported across the country by vast networks of cables and transformers.
What is direct current?
Current that flows in one direction.
What is alternating current?
A current that repeatedly reverses direction, it has a frequency of 50hz, which means its changing direction is 50 times per second.
What is alternating current caused by?
An alternating potential difference
What do alternating current and voltage graphs look like and why?
Wavy like a sound wave.
Because the value alternates between positive and negative.
Direct current is supplied by?
Cells and batteries
What is used for mains supply?
Alternating current.