A loop moves toward a stationary magnet. The induced current will:

  • A. Enhance the motion
  • B. Try to stop the approach
  • C. Become zero
  • D. Become alternating

Explanation

By Lenz's law the induced current sets up a field that opposes the change producing it, so the loop is repelled and work must be done to keep pushing it towards the magnet. That work is the source of the electrical energy generated, which makes Lenz's law a statement of energy conservation. A current that enhanced the motion would create energy from nothing.

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