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NEET2026PhysicsChapterActual

An electric heating coil dissipates 1000 ~W of average power when operated on an a.c. source. If the peak value of the alternating current flowing through the coil is 10 ~A , what is the rms voltage of the a.c. source? (Assume the coil is purely resistive)

Options

  1. A100 ~V
  2. B70.7 ~V
  3. C141.4 ~V
  4. D200 ~V

Correct answer

C. 141.4 ~V

Step-by-step solution

Average power dissipated in a purely resistive circuit is given by P = V_ rms I_ rms . The rms current is related to the peak current by I_ rms = I₀ 2 . Substituting the given peak current I₀ = 10 ~A : I_ rms = 10 2 = 5 2 ~A Using the power formula: 1000 = V_ rms 5 2 V_ rms = 1000 5 2 = 100 2 ~V Since 2 1.414 : V_ rms = 100 1.414 = 141.4 ~V Answer: 141.4 ~V

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