Question

The potential difference across the capacitor in volts, after two time constants, is approximately

• A. 2
• B. 7.6
• C. 10.4
• D. 12

Answer 1

Answer: (C)

10.4

$V_C=V_S(1-e^{\frac{-t}{\tau }})$

After 2 time constants ,

$V_C=V_S(1-e^{-2})$

$V_C=12(1-0.135135)=10.378$ V