**Unformatted text preview: **source voltage of 110 V. ( b ) Repeat for a 440-W bulb. 45. (II) A power station delivers 750 kW of power at 12,000 V to a factory through wires with total resistance 3.0 Ω. How much less power is wasted if the electricity is delivered at 50,000V rather than 12,000 V? 25–7 Alternating Current 49. (I) Calculate the peak current in a 2.7-k Ω resistor connected to a 220-V rms ac source. 55. (II) A heater coil connected to a rms 240-V ac line has a resistance of 44 Ω ( a ) What is the average power used? ( b ) What are the maximum and minimum values of the instantaneous power? General Problems 63. A person accidentally leaves a car with the lights on. If each of the two headlights uses 40 W and each of the two taillights 6 W, for a total of 92 W, how long will a fresh 12-V battery last if it is rated at 85A-h? Assume the full 12 V appears across each bulb....

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- Spring '14
- Finkenthal
- Physics, Current, Resistance, Work, Alternating Current, Volt, Resistor