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MHT CET202615 April 2026Morning ShiftPhysicsAlternating CurrentActual

A coil has inductive reactance 3 H. The ratio of its reactance when it is first connected to an a.c. source and then to d.c. source is

Options

  1. Azero
  2. B3
  3. Cinfinite
  4. D1.5

Correct answer

C. infinite

Step-by-step solution

The inductive reactance of a coil is given by X_L = L = 2 f L , where f is the frequency of the source. For an a.c. source, the frequency f > 0 , so the inductive reactance X_ L(ac) has a finite non-zero value. For a d.c. source, the frequency f = 0 , so the inductive reactance X_ L(dc) = 0 . The ratio of the reactance when connected to an a.c. source to that when connected to a d.c. source is: Ratio = X_ L(ac) X_ L(dc) = L 0 = Thus, the ratio is infinite. Answer: infinite

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