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# Isaac Physics: Discharging a Capacitor - What is halving time? watch

1. I am given that the capacitance is 100μF and the resistance is 200kΩ.
I have found (using the equation: Time = Resistance x Capacitance) that the time constant is 20s. They are now asking what the halving time is, what is the halving time, how can I find it?
2. (Original post by Aida Karabu)
I am given that the capacitance is 100μF and the resistance is 200kΩ.
I have found (using the equation: Time = Resistance x Capacitance) that the time constant is 20s. They are now asking what the halving time is, what is the halving time, how can I find it?
The halving time is the time taken for the voltage/current/charge of a capacitor to half when discharging the capacitor. To find it, multiply the time constant by ln 2.

If you equate an exponential decay graph of charge/voltage/current to half its original respective quantity, and rearrange for t, you'll get the half life.
3. (Original post by h3rmit)
The halving time is the time taken for the voltage/current/charge of a capacitor to half when discharging the capacitor. To find it, multiply the time constant by ln 2.

If you equate an exponential decay graph of charge/voltage/current to half its original respective quantity, and rearrange for t, you'll get the half life.
Thanks .

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Updated: February 8, 2017
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