Correct Option: (C) $g$
Step 1 (Governing Law & Physical Principle): [0.5 Mark]
According to Faraday’s Law of Electromagnetic Induction, an induced electromotive force (EMF) is generated in a conductor only when there is a change in magnetic flux linked with a closed loop. The induced current $I$ is given by:
$$I = \frac{\varepsilon}{R} = -\frac{1}{R} \frac{d\phi_B}{dt}$$However, for an induced current to flow, the circuit must be electrically continuous (closed).
Step 2 (Step-by-Step Logical Deduction): [0.25 Mark]
- In the given problem, the copper ring has a cut.
- Because the ring is not a closed loop, the induced EMF cannot drive a current through the ring.
- Since there is no induced current ($I = 0$), there is no magnetic force (Lenz's Law effect) to oppose the motion of the falling magnet.
- Consequently, no retarding force acts on the magnet.
Step 3 (Final Concluded Answer): [0.25 Mark]
Since the only force acting on the magnet is gravity, the magnet falls under free fall conditions. Therefore, its acceleration is equal to the acceleration due to gravity:
$$\vec{a} = \vec{g}$$Final Answer: (C) $g$
💡 EL10 Concept Insight: Think of the ring like a broken wire; because the path is cut, electricity can't flow around it to create a magnetic field that would push back against the magnet. Since nothing is pushing back, the magnet just falls normally as if the ring wasn't even there!