1. Concept: During the discharge of a capacitor through a resistor, the outgoing current drops exponentially over time. Power dissipation requires current.
2. Formula: $$ P = I^2 R \quad \text{where} \quad I(t) = I_0 e^{-t/RC} $$
3. Solution: - Because current decays according to the asymptotic function \( e^{-t/RC} \), the current only reaches exactly zero mathematically when \( t \to \infty \).
- Since Power strictly relies on Current (\( P = I^2 R \)), power dissipation only truly halts at mathematical infinity, despite being practically negligible much earlier.
4. Why other options are incorrect: At \( t = 0 \), power dissipation is at its absolute maximum. At 1 RC and 5 RC, current is still flowing (approx 37% and 1% of max current remain, respectively), meaning power is still being dissipated.
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