1. A constant current of 9 A exists in a wire for 15.0 min.

• a. How much total charge passes through a given point in the circuit during those 15.0 min?
• b. How many electrons would that be?
• c. If the charge were 700 C, then how much current flows through the circuit for 13.3 min?

2. Calculate the resistance of the lanterns of a 752 W airplane designed for 60 V.

3. If the resistance of the headlights of a car were 7.2 , then, calculate the electrical power (in watts) if the headlights were designed for 20 V?

4. An electric heater draws a constant 15.0 A on a 120 V line. How much power does it require and how much does it cost per month (31 days) if it runs 3.0 hours per day and the power company charges 21.2 cents per kWh?