Question

A Capacitor question. help please!

Answer 1

a. Determine the time constant of the circuit.\[\tau=\frac{20V}{0.2A}*5.6\mu F=0.56s\]b. Write the mathematical equation for the voltage v(c) following the closing of the switch.\[v_{c}=20(1-e^{\frac{-t}{0.56}})\]c. Determine the voltage v(c) after one, three, and five time constants.\[V_{c}=20(1-e^{-1})=12.64V\]\[v_{c}=20(1-3^{-0.33})=5.66V\]\[v_{c}=20(1-e^{-0.2})=3.62V\]But the text book is telling me that for the 3tau and 5tau constants are 19V and 19.87V
d. Write the equations for the current i(c) and the voltage v(R).
i think i can get this one.