Time needed to reduce charge of a capacitor

AI Thread Summary
To determine the time needed to reduce the charge of a 20 µF capacitor from 20 µC to 8 µC when discharged through a 1.0 kΩ resistor, the relevant equation is I = dQ/dt. The change in charge, dQ, is 12 µC. The initial voltage across the capacitor can be calculated using the capacitance and initial charge, which aids in finding the current. Understanding the relationship between charge, voltage, and resistance is crucial for solving this problem effectively.
catan
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Homework Statement


A 20 uF capacitor initially charged to 20 uC is discharged through a 1.0 kOlhms resistor. How long does it take to reduce the capacitor's charge to 8.0 uC?




Homework Equations



I=dQ/dt



The Attempt at a Solution



I know that dQ = 12 uC. What I can't figure out is how to get I from the given data. I'm assuming I need to use the 20 uF along with the resistance to find the I but I don't know how that can be done. I appreciate any help, thanks!
 
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catan said:

Homework Statement


A 20 uF capacitor initially charged to 20 uC is discharged through a 1.0 kOlhms resistor. How long does it take to reduce the capacitor's charge to 8.0 uC?




Homework Equations



I=dQ/dt



The Attempt at a Solution



I know that dQ = 12 uC. What I can't figure out is how to get I from the given data. I'm assuming I need to use the 20 uF along with the resistance to find the I but I don't know how that can be done. I appreciate any help, thanks!

I think you need more relevant equations. Do you know what the initial voltage is across the capacitor?
 
I figured it out
 

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