Question

question 3 (1 point)
a circular coil lies flat on a horizontal table. a bar magnet is held above its center with its north pole pointing down. the stationary magnet induces (when viewed from above)
no current in the coil.
a clockwise current in the coil.
a counterclockwise current in the coil.
a current whose direction cannot be determined from the information given.

Explanation:

To determine the induced current, we use Faraday's Law and Lenz's Law. Faraday's Law states that an electromotive force (and thus current) is induced when there is a change in magnetic flux. Lenz's Law states that the induced current will flow in a direction that opposes the change in magnetic flux.

In this case, the bar magnet is stationary above the coil. Since the magnet is not moving, the magnetic flux through the coil is constant (no change in flux). According to Faraday's Law, a changing magnetic flux is required to induce an electromotive force (and hence a current) in the coil. Since the flux is constant (stationary magnet), there is no induced current.

Answer:

no current in the coil.