Solving a Basic RC Circuit: Charge on Capacitor from 537 to 195 μC

AI Thread Summary
To determine how long it takes for the charge on a capacitor to drop from 537 μC to 195 μC in an RC circuit, the time constant equation Qf = Qo e^(-t/T) is used, where T is the product of resistance (1,923 Ohms) and capacitance (1,251 microFarads). By calculating the time constant and solving for t, the time can be found. The discussion confirms that the approach is correct and that the user successfully checked their answer in an online assignment. The exchange highlights the application of theoretical knowledge in practical problem-solving. Understanding RC circuits is essential for mastering related physics concepts.
CompEguy
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Homework Statement



The capacitor in the circuit has 537 μC of charge on it at t=0. The resistor is 1,923 Ohms, and the capacitor is 1,251 microFarads

How long will it take for the charge on the capacitor to drop to 195 μC?

Please use only SI (metric) system units in your answer!

Homework Equations



?? I do not know.


The Attempt at a Solution



I am so lost.
 

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CompEguy said:

Homework Statement



The capacitor in the circuit has 537 μC of charge on it at t=0. The resistor is 1,923 Ohms, and the capacitor is 1,251 microFarads

How long will it take for the charge on the capacitor to drop to 195 μC?

Please use only SI (metric) system units in your answer!

Homework Equations



?? I do not know.


The Attempt at a Solution



I am so lost.

Use the time constant equation for a drop:

Qf= Qo e^-t/T, where T is the time constant, or R x C. You know or can find all of these variables, and solve the equation for t. Make sure you convert your C to Farads.

I think this is correct. I'm only an undergrad student, but just had an exam containing RC circuits and did really well.
 
Thank you. This did work. It is an online assignment so I can check my answer right away.
 
CompEguy said:
Thank you. This did work. It is an online assignment so I can check my answer right away.

Cool. Glad I actually did learn something in Physics class lol.
 
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