1. 4.2.3B Electrical Power What About Watts?

2. Power Law Moving electrons (current) requires ENERGY How much energy gets used depends on: Strength of push – VOLTAGE Rate of flow – CURRENT

3. A 12 volt battery is connected to a circuit which allows 10 amperes of current to flow. –What is the power output of this circuit? Example #1 P = IV P = (12 V)(10 A) P = 120 W

4. A 100 watt light bulb is connected to a 120 volt power supply. –What amount of current must pass through the light bulb? Example #2 P = IV 100 W = (120 V) I I = 0.833 A

5. A 2.0 ampere current passes through a circuit with a 300 ohm resistance. –What is the power generated in this circuit? Example #3 P = I 2 R P = (2.0 A) 2 (300 Ω) P = 1200 W or 1.2 kW

6. End of 4.2.3B – PRACTICE