Lenz's Law states that the induced current's magnetic field does what to oppose changes in flux?

• A. Reinforces the change in magnetic flux
• B. Aligns with the applied magnetic field
• C. Has no relation to magnetic flux
• D. Produces a magnetic field that opposes the change in magnetic flux

Answer: (D)

The main idea here is that induced currents try to resist changes in magnetic flux through a loop. According to Lenz's Law, the magnetic field generated by the induced current is directed to oppose the change in flux. If the external flux through the loop is increasing in a certain direction, the induced field will point in the opposite direction to oppose that increase; if the flux is decreasing, the induced field will point in the same direction as the original field to oppose the decrease. This opposition is also captured by the negative sign in Faraday’s law, emf = -dΦ/dt. The description that the induced magnetic field produces a field opposing the change in flux is the correct way to express this rule. The other ideas—reinforcing the change, aligning with the applied field, or having no relation—do not reflect this opposing response.