# Lightbulb resistance and efficiency

A GE Softwhite lightbulb is rated as follows:

rated power = 60 W ;

rated optical power = 820 lumens (lm)

1 lm = 1/680 W

operating life = 1.5 h

rated operating voltage = 115 V

The resistance of the filament of the bulb, measured with a standard multimeter is 16.7 ohms. When the bulb is connected into a circuit and is operating at the rated values given above, determine the resistance of the filament and efficiency of the bulb.

***answer should be 220.4 ohms and 2.009%*** I didn't get the same answer...

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lightbulb resistance and efficiency

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AGE Softwhite lightbulb is rated as follows:

rated power = 60 W ;

rated optical power = 820 lumens (lm)

1 lm = 1/680 W

operating life = 1.5 h

rated operating voltage = 115 V ...

#### Solution Summary

The solution involves step-by-step calculations and explanation for finding the resistance of the filament and efficiency of a light bulb.