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NEET2012PhysicsCurrent ElectricityActual

If voltage across a bulb rated 220 ~V -100 ~W drops by 2.5 % of its rated value, the percentage of the rated value by which the power would decrease is

Options

  1. A20 %
  2. B2.5 %
  3. C5 %
  4. D10 %

Correct answer

C. 5 %

Step-by-step solution

Power P= V^2 R For small variation aligned P P 100 % & = 2 V V 100 % & =2 2.5=5 % aligned Therefore, power would decrease by 5 % .

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