Repair for missing figure — “The capacitor voltage at the beginning of the second pulse is ______. Assume the capacitor is initially uncharged.” Without the component values, period, and τ relative to the pulse timing, can we determine the exact voltage?

Introduction / Context:
The initial voltage of a capacitor at the start of a subsequent pulse depends on how much it charged during the previous high interval and how much it discharged during the low interval. Both are governed by τ = R * C and the specific high/low times (duty cycle). With no numeric values or figure, the exact voltage cannot be computed.

Given Data / Assumptions:

• Capacitor starts uncharged at t = 0.
• Repetitive pulse train drives an RC network.
• Component values and period/duty are not provided.

Concept / Approach:
Over one period, the capacitor charges toward a level during “high” and discharges during “low,” each following v_C(t) = V_final + (V_initial − V_final) * exp(−t/τ). The steady-state beginning-of-pulse value is found by equating the end of one interval to the start of the next. This requires τ and the timing parameters; absent them, there is no unique voltage.

Step-by-Step Solution:

Verification / Alternative check:
Examples with τ ≪ period produce near-zero start voltages; τ ≫ period produces significant memory (v1 near prior average), proving dependence on missing data.

Why Other Options Are Wrong:

• Fixed percentages (36.8%, 63.2%) correspond to exactly 1τ intervals, not universal outcomes.
• “Always equals amplitude” or “always zero” are special cases only.

Common Pitfalls:
Assuming the 1τ percentages apply to any arbitrary pulse timing; they apply only when interval length equals τ.

Final Answer:
Cannot be determined from the information provided.