Question

4.2.4 quiz: electromagnetism
breanna connected a wire coil to a lightbulb to demonstrate that a moving magnet can cause a current to flow in a wire. then she moved a bar magnet first toward and then away from the wire coil. however, she could not make the lightbulb light up. which factor could explain this outcome?
a. she moved the bar magnet toward the wire coil too quickly.
b. she did not move the bar magnet through the wire coil.
c. she moved the bar magnet below the wire coil instead of above the coil.
d. she did not connect the wire coil in the correct direction.

Explanation:

Electromagnetic induction requires a changing magnetic field through the coil. Moving the magnet through the coil (changing the magnetic flux) induces current. Not moving it through (no significant flux change) won't light the bulb. Quick movement (A) would induce more current. Position (C) or connection direction (D) (assuming a complete circuit) doesn't prevent induction if flux changes.

Answer:

B. She did not move the bar magnet through the wire coil.