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How to determine the brightness of a light bulb

  • Thread starter cy19861126
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  • #1
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In general, does more current/less resistence mean the brighter of the light bulb? How does voltage take into account in this case
 

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  • #2
ranger
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Both the current and voltage contributes to the brightness. It just depends on the configuration. If an incandescent is 100% efficient (with it isnt btw), that means all power (V*I) would be used to produce visible light rather than 90% being wasted as heat.
 
  • #3
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"Brightness" is a measure of power, so at constant voltage power is I^2R. If resistance is decreased and current is increased by an equal factor, the increase in current counts for more and the bulb will appear brighter
 

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