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प्रश्न
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
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उत्तर
Given power of lamp = 100 watt
rate of dissipation of light = 10 J/s
Therefore, percentage of electrical energy converted into light energy = `10/100 xx 100%` = 10%
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