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AIIMS2002PhysicsElectromagnetic Induction

Assertion : The quantity L / R possesses dimension of time. Reason : To reduce the rate of increase of current through a solenoid, we should increase the time constant (L / R) .

Options

  1. AIf both the assertion and reason are true and reason is a correct explanation of the assertion.
  2. BIf both assertion and reason are true but assertion is not a correct explanation of the assertion.
  3. CIf the assertion is true but the reason is false.
  4. DIf both assertion and reason are false.

Correct answer

C. If the assertion is true but the reason is false.

Step-by-step solution

Induced e.m.f. ( )= L d i d t and current (i)= R = 1 R L d i d t or, L R = i d t d i = current time current = time. In order to increase the rate of increase of current through a solenoid, we increase the time constant (L / R) . Since L of the given solenoid is constant, therefore we use a high resistance in series with it.

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