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True or not true? It takes as much energy (read: electricity) to turn on an electric light as it does to run one for 20 minutes?

Not true. At least not for incandescent lights. I have heard that may be true for fluorescences though. For incandescence (the ordinary household bulbs) the turn-on energy amounts to at most a few seconds of ordinary running time. It does involve an increased current through the bulb that may shorten its lifetime though - you may have noticed bulbs tend to go out almost immediately after being turned on.

Arthur Smith

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