P1 - Electrical Energy Flashcards
What is power
The rate of energy transfer
What’s the equation of power and the units
P = E/T
P - power (watt, or kilowatt (watt X 1000))
E - Energy (J)
T - Time taken to transfer the energy (seconds)
What is a kilowatt hour
The energy supplied to a 1kw appliance in 1 hour
How to find the cost of electrical energy supplied
Total cost = number of KWH X cost per KWH
The price of 1KWH of electrical energy is 9p. How much does it cost to use a 60W electric light for 4 hours?
2.16 pence
What affects how cost effect an appliance is?
The cost of buying the appliance
The cost of running the appliance
How long it lasts for
Environmental costs
What’s the pay back time?
How long it takes for the approach to pay for itself in the cost of energy saved by installing it.
