Math Problems Involving Electricity
- Brad has a new flashlight that runs on one 8-volt battery. How much current flows
through this circuit if the bulb has 2 ohms of resistance?
- If your fingers are damp and offer a resistance of only 1200 ohms, how much current
will pass through them if you touch the terminals of a 6-volt battery?
- If your hair dryer draws 10 amps of current on a 120-volt circuit, how much power does it use?
- Shane's 100-watt radio draws 7 amps of current on a 120-volt circuit. What is the
resistance in the radio?
- It is Lisa's night to clean up the kitchen, but she's anxious to get started on her physics
homework. While loading the dishwasher, she calculates how many amps of current it
uses on a 120-volt circuit. What did she find?
- Audrey fell off her horse during riding lessons and got all of her clothes dirty. How
much energy is used by an 1800-watt washing machine that runs 30 minutes and a
4000-watt clothes dryer that runs for 1 hour? If electricity costs $0.06 per kilowatt-hour, how much did it cost Audrey to wash and dry her clothes?
Excerpted from Hands-On General Science Activities with Real-Life Applications.

