Solving the Capacitor Charging Problem

Thread starter ShEeRMiLiTaNt
Start date Oct 15, 2012
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Capacitor Charging

AI Thread Summary

To determine the time required to charge a 7.7 x 10^-7 farad capacitor to 70V when connected to a 190V battery through an 11000 ohm resistor, the charge (q) is calculated as 5.39 x 10^-5C using the formula q = CV. The equation q = q0e^(-t/RC) is then applied, where q0 is the initial charge, found by multiplying the capacitance by the battery voltage (190V). The discussion focuses on solving for the time variable (t) in the equation. Clarification on the value of q0 is essential for further calculations.

Oct 15, 2012

ShEeRMiLiTaNt

Hello Everyone,
I need to solve this problem:
How many seconds does it take to charge a 7.7 x 10^-7 farad capacitor to 70V if it is initially uncharged, then connected to a 190V battery through a 11000 ohm resistor.

What I have so far:
q = CV
q = (7.7 x 10^-7f)(70V)
q = 5.39 x 10^-5C

q = q₀e^-t/RC
5.39 x 10^-5 = q₀e^{-t/(11000)(7.7 x 10^-7)}

What is q₀ here?

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Oct 15, 2012

andrien

just multiply the capacitance by 190V.

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