🔍 Key Concepts

• Relationship between power (watts), voltage, current, and resistance • How to use the power formula to solve for current when power and resistance are known • Unit checking to be sure the final current value is reasonable for the given resistance and power

💭 Think About

• Which power formula includes both power and resistance, and allows you to solve directly for current? (Hint: start from P = I × V and Ohm’s Law V = I × R) • After you derive the formula for current in terms of power and resistance, what is the square root telling you about how current relates to power and resistance? • If a resistor has a very large resistance (5000 ohms), would you expect the current at 200 watts to be relatively small or large?

✅ Before You Answer

• Write and rearrange the correct formula so that current (I) is alone on one side before plugging in numbers • Be sure you square current or voltage in the correct place when combining formulas; double-check exponents • After calculating, compare your numerical answer with the choices to see if it matches exactly or if it suggests choosing None of the above