the cost of electricity Flashcards
1
Q
what is power measured in?
A
watts (W) or kilowatts (KW)
A 5 KW appliance transfers 5000 J in 1 S
2
Q
what are the standard units of electrical energy?
A
kilowatt-hours (kWh) (not joules)
3
Q
what is a kilowatt-hour?
A
the amount of electrical energy used by a 1KW appliance left on for one hour
4
Q
what are the two formulas for calculating the cost of electricity?
A
no of units (kWh) used= power (in kW) X time (in hours)
cost= no of units X price per unit
5
Q
what is energy measured in?
A
Joules (J) 1 J is the amount of energy transferred by a 1 W appliance in 1 S
