Question

an electric current is produced using a bar magnet and a solenoid. which changes will cause a decrease in the electric current produced? check all that apply. using more wire loops in the solenoid using fewer wire loops in the solenoid using a stronger magnet moving the solenoid instead of the magnet moving the magnet more slowly

Explanation:

To determine which changes decrease the induced current, we use Faraday's Law of Electromagnetic Induction, which states that the induced electromotive force (and thus current) is proportional to the rate of change of magnetic flux. Magnetic flux depends on the number of wire loops, the strength of the magnet, and the speed of relative motion between the magnet and solenoid.

• Using more wire loops: Increases the magnetic flux linkage, so induced current increases. Eliminate this option.
• Using fewer wire loops: Decreases the magnetic flux linkage, so induced current decreases. This is valid.
• Using a stronger magnet: Increases the magnetic field, so magnetic flux (and thus current) increases. Eliminate this option.
• Moving the solenoid instead of the magnet: Relative motion (needed for induction) is still present; this does not decrease current. Eliminate this option.
• Moving the magnet more slowly: Decreases the rate of change of magnetic flux, so induced current decreases. This is valid.

Answer:

B. using fewer wire loops in the solenoid
E. moving the magnet more slowly

(Note: The options are labeled as per the original list: 1. using more..., 2. using fewer..., 3. using stronger..., 4. moving solenoid..., 5. moving magnet more slowly. So the correct options are the second and fifth, corresponding to "using fewer wire loops in the solenoid" and "moving the magnet more slowly".)