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### 1003-B: The Power Formula

• Topic Cluster: Electric Circuits
• Topic: DC Circuit Math 1: Batteries and Resistors
• Objective: Use both the power formula and Ohm's Law to solve for power or other quantities.
• Content: Power is equal to current times voltage; this formula can be combined with Ohm's Law.
• Level: 1

#### BACK to Ladder DC Circuit Math 1: Batteries and Resistors

In the previous pod, we learned the main formula for an electric circuit: Ohm's Law $$V = IR$$. In this pod, we will learn a second crucial formula for comprehending electric circuits: The power Formula $$P = IV$$.

$$P = I V$$

1. I have a current of 5 Amps and I have a 12 Volt battery. What is my power?
2. I have a current of 3 Amps and a 30 Volt battery. What is my power?
3. I have a 100 Watt light bulb hooked up to an outlet, which means it has 120 Volts. What is its current?
4. My vacuum cleaner uses 1100 Watts, and I hook it up to an outlet, which means it has 120 Volts. What is its current?
5. I have a 300-Watt device, and I know there is 2 Amps of current going through it. How much voltage does it have?
6. I hook up a 4-volt battery, and it produces a current of 0.3 Amps through my light bulb. How much power does the light bulb have?
7. I hook up two 4-volt batteries, and it produces a current of 0.6 Amps through my light bulb. How much power does my light bulb have?