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JEE Main202224 Jun 2022Morning ShiftPhysicsAlternating CurrentActual

A resistance of 40 Ω is connected to a source of alternating current rated 220 V , 50 Hz . Find the time taken by the current to change from its maximum value to the rms value :

Options

  1. A2 . 5   ms
  2. B1 . 25   ms
  3. C2 . 5   s
  4. D0 . 25   s

Correct answer

A. 2 . 5   ms

Step-by-step solution

The current in AC is of the form of i = i 0 sin ω t . The maximum current is i 0 and rms current is i 0 2 . The change in the phase when current change from maximum to rms value is π 4   rad . Therefore, the time taken for the same will be, t = ∆ ϕ ω = π 4 × 2 π × 50 = 2 . 5   ms .

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