How much power does a hair dryer use if it draws 15 A of current at 100 V?

How much power does a hair dryer use if it draws 15 A of current at 100 V?

• A. 1500 W
• B. 150 W
• C. 15 W
• D. 15000 W

Answer: (A)

Power in an electrical circuit is found by multiplying the voltage by the current (P = V × I). If a hair dryer operates at 100 volts and draws 15 amperes, its power is 100 × 15 = 1500 watts. So the correct amount is 1500 W (about 1.5 kilowatts). The other numbers don’t fit because they would require different combinations of voltage and current than 100 V and 15 A. Real-world hair dryers around 1.5 kW match this calculation.

Power in an electrical circuit is found by multiplying the voltage by the current (P = V × I). If a hair dryer operates at 100 volts and draws 15 amperes, its power is 100 × 15 = 1500 watts. So the correct amount is 1500 W (about 1.5 kilowatts). The other numbers don’t fit because they would require different combinations of voltage and current than 100 V and 15 A. Real-world hair dryers around 1.5 kW match this calculation.