Strictly speaking, the equation q=Q_0e^{-t/RC} implies that an infinite amount of time is required to discharge a capacitor completely. Yet for practical purposes, a capacitor may be considered to be fully discharged after a finite length of time. To be specific, consider a capacitor with capacitance C connected to a resistor R to be fully discharged if its charge q differs from zero by no more than the charge of one electron.(adsbygoogle = window.adsbygoogle || []).push({});

I could do everything except explaining why Part C's answer is correct

Part A

Calculate the time required to reach this state if C = 0.910 microF, R = 690 kilo ohms, and Q_0 = 6.80 microC.

t=19.7s

Part B

How many time constants is this?

31.4 time constants

Part C

For a given Q_0, is the time required to reach this state always the same number of time constants, independent of the values of C and R?

yes

Part D

Why or why not? (in response to Part C)

Part D is what i cant explain. Can anyone help?

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# Homework Help: RC Circuits charge homework

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