To charge a 100 µF capacitor in 15 seconds, use a resistor.
A)35 kΩ
B)15 kΩ
C)30 kΩ
D)25 kΩ

Question

Quizplus · Accepted Answer

The time constant τ = R*C, where R is resistance and C is capacitance. For a 100 µF capacitor and a desired time constant of 15 seconds, R = τ/C = 15s / 100µF = 150,000Ω or 150 kΩ. However, the question might be asking for a specific charging percentage, typically 63.2% (1 time constant), which would require a resistor of 30 kΩ for a full charge in 15 seconds.

To Charge a 100 µF Capacitor in 15 Seconds, Use