Question

4.3.2 test (cst): electromagnets
question 16 of 20
how does electromagnetic induction in a moving loop of wire cause an electric generator to produce an electric current?
a. mechanical energy flows out of the magnets and into the electric charges in the loop of wire.
b. charged particles flow when the loop of wire is attracted by the magnetic field of the magnets.
c. electrons flow from the magnets into the loop of wire and continue to flow within the wire.
d. charged particles flow within the wire because they are pushed by the magnetic field of the magnets.

Explanation:

• Option A: Magnets don't have mechanical energy flowing out to electric charges in this context. Mechanical energy is related to motion (like rotation of the loop), but it's not about energy "flowing out of magnets" in the way described.
• Option B: It's not just about attraction. The key is the force on charged particles due to the magnetic field and the motion of the loop (or the change in magnetic flux through the loop). Attraction is too simplistic an explanation for the current - generating process.
• Option C: Electrons don't flow from magnets into the wire. The wire has its own electrons (in a conductor, there are free electrons). The process is about the movement of the wire's own electrons due to the magnetic field interaction, not electron transfer from magnets.
• Option D: According to the principle of electromagnetic induction, when a loop of wire moves in a magnetic field (or the magnetic flux through the loop changes), the magnetic field exerts a force on the charged particles (electrons in the wire). This force causes the charged particles to flow, creating an electric current.

Answer:

D. Charged particles flow within the wire because they are pushed by the magnetic field of the magnets.