When the magnetic flux through a loop increases, the induced current flows such that its own magnetic field opposes this increase. What is the rule called?

When the magnetic flux through a loop increases, the induced current flows such that its own magnetic field opposes this increase. What is the rule called?

• A. Faraday's law
• B. Lenz's law
• C. Gauss's law
• D. Ampere's law

Answer: (B)

Lenz's law states that the induced current in a closed loop flows in a direction that creates a magnetic field opposing the change in magnetic flux that produced it. So when the external magnetic flux through the loop increases, the loop carries a current whose magnetic field works against that increase. The rule is often written through Faraday’s law with a negative sign: emf = - dΦ/dt, where the minus sign encodes this opposition in direction. This is why the induced current acts to oppose the change rather than reinforce it. Related laws include Gauss's law, which relates electric flux to charge, and Ampere's law, which links magnetic fields to currents; they describe other aspects of electromagnetism but not the directional opposition described by Lenz's law.

Lenz's law states that the induced current in a closed loop flows in a direction that creates a magnetic field opposing the change in magnetic flux that produced it. So when the external magnetic flux through the loop increases, the loop carries a current whose magnetic field works against that increase. The rule is often written through Faraday’s law with a negative sign: emf = - dΦ/dt, where the minus sign encodes this opposition in direction. This is why the induced current acts to oppose the change rather than reinforce it. Related laws include Gauss's law, which relates electric flux to charge, and Ampere's law, which links magnetic fields to currents; they describe other aspects of electromagnetism but not the directional opposition described by Lenz's law.