Final answer:
The minus sign in Faraday's Law of Induction signifies that the induced emf will always work to oppose changes in magnetic flux, conforming to Lenz's Law. This negative sign ensures the induced current is in a direction that opposes the initial change, maintaining conservation of energy within the system.
Step-by-step explanation:
The minus sign in Faraday's Law of Induction (emf=-N(ΔΦ/t)) is very significant. It represents Lenz's law, which states that the induced electromotive force (emf) always works in a direction that opposes the change in magnetic flux. This opposition is crucial for maintaining the conservation of energy. The minus sign indicates that the direction of the induced emf and the subsequent current created by it will oppose the initial change in magnetic flux through a circuit.
In the law emf = -N(ΔΦ/Δt), the negative sign serves a purpose: it negates the negative change in the magnetic field, resulting in a positive current flowing in the direction of the original magnetic field. This alignment is essential for preserving the natural tendency of systems to resist changes in their state, as articulated in Lenz's Law. The law's predictive power allows us to determine the direction of the induced current and thus the behavior of the circuit in response to changes in magnetic fields.