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Electrical circuit help


Guest richardcates

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Guest richardcates

:confused: I need help with a question and wonder if anyone can point me in the right direction.

 

Two capacitors of 20 microfarad's and 40 microfarad's are connected in series. A constant voltage of 50 V is applied to the combination, it is then removed and replaced with a short circuit. Determine the final charge on each capacitor ?

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:confused: I need help with a question and wonder if anyone can point me in the right direction.

 

Two capacitors of 20 microfarad's and 40 microfarad's are connected in series. A constant voltage of 50 V is applied to the combination' date=' it is then removed and replaced with a short circuit. Determine the final charge on each capacitor ?[/quote']

Are you sure you worded the question correctly?

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Maybe your question has been stated wrongly.

As YT2095 siad, the final charge left on each capacitor will be zero after you leave the circuit for at least a few time constants (After the transient effects have dissipated).

 

This is because all the charge will have been dissipated by through the short-circuit link.

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it would be different if the "Short" was a fixed resistance, and a time index was given :)

 

edit: I`ve had a look around for you, and figure this maybe helpfull to you, rather than me trying to explain it text.

the part at the bottom will be the most applicable I recon :)

http://www.eatel.net/~amptech/elecdisc/capacitr.htm

 

Double edit, the graphs are for charging sure, but apply equaly to the discharge, just reverse the curve :)

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Maybe your question has been stated wrongly.

As YT2095 siad' date=' the final charge left on each capacitor will be zero after you leave the circuit for at least a few time constants (After the transient effects have dissipated).

 

This is because all the charge will have been dissipated by through the short-circuit link.[/quote']

Sorry, I thought the answer was obvious.

 

BTW, a 20 µf capacitor would likely be tantalum, so without the short, the charge would be zero in a short period of time through dielectric absorption.

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