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Join Date: Mar 2005
Location: Travelers Rest, South Carolina
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Re: Basic basic electrical question (Ohm's law)

Quote:
Originally posted by cowtown
What am I doing wrong here guys-

I have a tiny auto light bulb and want to know its wattage so I can go shopping.

It draws 120mA as measured by an in-serries ammeter at 12VDC. Ohms law says that means it is approx. a 1.44 watt bulb and its resistance is 100ohms.

But measured filiment resistance is 9.5 ohms...huh? What's wrong here?
What does the manual call for in the position the bulb goes in? You're not working on a car without a maintenance manual open are you?
Old 04-01-2006, 04:43 PM
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