P1.3 Electrical Energy Flashcards
1
Q
List three common electrical appliances.
A
- Lamps - produce light
- speakers - sound energy
- TV - produce light and sound energy
2
Q
What is the power of an appliance?
A
the rate at which it transfers energy
3
Q
What is the unit of power?
A
the watt (W)
4
Q
how many watts is 1 kilowatt?
A
1000 watts?
5
Q
What is the efficiency equation in terms of power?
A
Efficiency=(Useful power out/total power in)x100%
6
Q
What is a kilowatt-hour?
A
the energy supplied to a 1 kW appliance in 1 hour.
7
Q
Total cost =
A
number of kW h x cost per kW h
8
Q
Define ‘Cost Effectiveness’.
A
Getting the best value for money
9
Q
what is the ‘payback time’ of an appliance or installation?
A
The time it takes to pay for itself in terms of energy savings.
10
Q
what quantity is measured in kilojoules?
A
Energy
