1. Top 10 List – Electrical Energy

2. 1. A series circuit has one loop for electricity to flow through
1. A series circuit has one loop for electricity to flow through. If the loop (circuit) is broken, an open circuit is created which disables all connected on the circuit.

3. 2. A parallel circuit contains two or more branches for the current to move through. If one branch is disconnected, the remaining branches continue to work.

4. 3. Fuses - pieces of metal; melt when too hot; stops the current; requires replacement.

5. 4. Circuit Breakers - heat up; cause a switch to flip; stop the current; switch to turn back on.

6. 5. Electrical power is the rate at which electrical energy is converted into other forms of energy (ex: thermal).

7. P = I x V 6. Power = current x voltage difference P = watts I = amps
V = volts

8. 7. Kilowatt-hour is the unit of electrical energy.
Equal to 1,000 W of power for 1 hour.

9. 8. Electrical energy depends upon the power required by the appliance and how long it is used.
Energy = Power x Time
E = P x T
E=(kWh)
P = (kW) (if W, then / by 1,000)
T = (h)

10. 9. Practice Problems
You use your fan for 3 h each day. It has a power rating of 50W. How much energy does it use in one day? (Answer in kWh.)
A 100-W light bulb has a power rating of 100W. How much energy in kWh is used when you leave it on for 5h?

11. 10. The cost of electricity.
You fall asleep with the television on and wake up 7 hours later. The television requires .3kW of power to operate. The cost of electricity is .20 per kWh. How much money did you waste by leaving the television set on?