Question

1. The terminals of a 0.70 V watch battery are connected by a 130-m-long gold wire with a diameter of 0.100 mm . What is the current in the wire? Express your answer using three significant figures in mA

2. A waterbed heater uses 500 W of power. It is on 35 % of the time, off 65 % .What is the annual cost of electricity at a billing rate of $0.12 per kWhr? Express your answer using two significant figures In dollars.

3. The voltage across the terminals of a 9.0 V battery is 8.5 V when the battery is connected to a 50 Ω load. What is the battery's internal resistance? Express your answer with the appropriate units.

4. What is the resistance of a 1700 W (120 V) hair dryer? What is the current in the hair dryer when it is used In A.

Answer 1

-92- 0.7 03.87 304 1 155 8 630 0 Sots