Power Ratings
Physics: AQA GCSE Higher, topic 2.4.3
Power Rating of Appliances
Appliances in the EU have a label or panel that tells you what the power rating of the appliance is.
Power label
- This power label can be used to calculate the current required by the appliance using the equation:
- power = potential difference x current.
- power = current 2 x resistance.
- 230 V is the potential difference across the mains power supply in the UK.
Work done per second
- We can work out how much energy an appliance transfers using the power rating and the equation:
- energy transferred = power x time.
- energy transferred = charge x potential difference.
- For example, a 100W lamp will use 100J of energy each second.
Test yourself on Power Ratings
What is the potential difference across the mains power supply in the UK?