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JEE MainPhysicsElectromagnetic Induction

Three identical coils C₁ , C₂ and C₃ are placed such that they share a common axis, with C₂ initially exactly midway between C₁ and C₃ . Coil C₁ carries a steady anti-clockwise current and coil C₃ carries a steady clockwise current. If coil C₂ is mechanically pushed to move along the common axis towards C₃ , the net magnetic force acting on C₂ due to the induced current will be

Options

  1. ATowards C₃
  2. BTowards C₁
  3. CZero
  4. DRadially outward

Correct answer

B. Towards C₁

Step-by-step solution

According to Lenz's law, the direction of the induced current is such that it opposes the cause producing it. The cause of the induced current in C₂ is its mechanical motion towards C₃ . Therefore, the magnetic force resulting from the induced current must oppose this motion, meaning the net magnetic force on C₂ will act in the direction opposite to its velocity, which is towards C₁ . Alternatively, this can be verified by finding the induced current direction. Let the common axis be the z-axis. C₁ (anti-clockwise)

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