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NEETPhysicsElectromagnetic Induction

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): If the angular speed of a coil rotating continuously in a uniform magnetic field is doubled, both the maximum induced EMF and the total charge flowing through the circuit, during the time the flux changes from its maximum positive to maximum negative value, are doubled. Reason (R): The maximum indu

Options

  1. ABoth (A) and (R) are true and (R) is the correct explanation of (A)
  2. BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
  3. C(A) is true but (R) is false
  4. D(A) is false but (R) is true

Correct answer

D. (A) is false but (R) is true

Step-by-step solution

The maximum induced EMF in a rotating coil is given by E_ max = NAB . Thus, E_ max is directly proportional to the angular speed . If is doubled, E_ max doubles. However, the total charge flowing through the circuit is given by q = R , where is the net change in magnetic flux and R is the resistance. The change in flux from maximum positive ( +NAB ) to maximum negative ( -NAB ) is 2NAB . Therefore, the total charge flowing is q = 2NAB R , which is independent of the angular speed and the time taken. Hence, when the

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