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cowtown cowtown is offline
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Join Date: Sep 2002
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Basic basic electrical question (Ohm's law)

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?
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Old 04-01-2006, 01:31 PM
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