Fuels for power Flashcards
What are the power ratings for electrical appliances.
watts (W) or kilowatts (kW)
Power Calculation
power = voltage x curent
Energy Calculation
energy supplied = power x time
Unit for electrical energy used in the home?
kilowatt-hours (kWh)
Cost of Electricity Used
cost of electricity used = energy used x cost per kWh
When do we pay for less electricity?
We pay for less electricity during the night when not as much is needed, but it still has to be produced.
The choice of energy sources depends on several factors:
- Availability.
- Ease of extraction.
- Effect on environment.
- Associated risks.
What is the National Grid?
A series of transformers and power lines that transport electricity from power stations to the consumer.
How high can step-up transformers in the National Grid increase voltage.
400,000V
What does the high voltage in the National Grid lead to?
- Reduced energy loss.
- Reduced distribution costs.
- Cheaper energy for consumers.
Why are step-down transformers used?
So the consumers have a more suitable level of voltage.
What does current do to a wire?
When a current passes through a wire the wire gets hot. The greater the current, the hotter the wire.
What happens when a transformer increases the voltage?
The current is reduced which means there is less of a heating effect and therefore less energy being lost to the environment.
