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Concepts Of Physics MCQ Edition [Volume 2]PhysicsAlternating Current

A capacitor behaves as an infinite resistance for

Options

  1. AAC
  2. Bneither DC nor AC
  3. CDC
  4. Dboth DC and AC

Correct answer

C. DC

Step-by-step solution

The capacitive reactance of a capacitor is given by X_C = 1 C = 1 2 f C , where f is the frequency of the current. For direct current (DC), the frequency f = 0 . Substituting f = 0 in the formula, we get X_C = . Thus, a capacitor offers infinite resistance to DC and blocks it completely. For alternating current (AC), f > 0 , so X_C has a finite value.

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