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JEE Main202431 Jan 2024Evening ShiftPhysicsCurrent ElectricityActual

By what percentage will the illumination of the lamp decrease if the current drops by 20 % ?

Options

  1. A46 %
  2. B26 %
  3. C36 %
  4. D56 %

Correct answer

C. 36 %

Step-by-step solution

Power through the resistor is given by, P = I 2 R . Now, P int = I 2 int R and P final = 0 .8 I int 2 R Therefore, % change in power = P final − P int P int × 100 = 0 .64 − 1 × 100 = − 36 %

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