Capacitor and resistor in series.

[GomerPyle]

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If you have a battery connected to a capacitor THEN a resistor in series, what role does the resistor play in charging the capacitor? Since current doesn't flow through a capacitor, does the resistor even have a role?

In an aamc question (self assessment), the electrical potential energy that the capacitor gains as it charges is less than the work done by the battery throughout the charging process because energy is lost by heating the resistor. So the resistor DOES get current then? How does the battery supply energy to both charging the capacitor and heating the resistor if the resistor is in series AFTER the capacitor and current flows to the capacitor first?

Thanks.

 

[onedirection]

The resistor has no role, you are correct; that's assuming capacitor is fully charged because then Vcap = Vbat and no voltage would exist between Battery and capacitor to move electrons out, so there's no current

However if the resistor and capacitor were in parallel, the resistor would have a role

Okay I read the rest of your question

If the capacitor isn't fully charged, then Vcap =/= Vbattery, so there's still electrons flowing driven by the Potential difference between the two things leading to a current

Hypothetically if a capacitor and a resistor were in series and the battery is turned on at t = 0; Qc = 0 and V = IR

Over time Vcap = Vbat as the Capacitor fills up with Charge Q = CV; and Vres = 0 as Current goes to zero

 

[GomerPyle]

The resistor has no role, you are correct; that's assuming capacitor is fully charged because then Vcap = Vbat and no voltage would exist between Battery and capacitor to move electrons out, so there's no current

However if the resistor and capacitor were in parallel, the resistor would have a role

Okay I read the rest of your question

If the capacitor isn't fully charged, then Vcap =/= Vbattery, so there's still electrons flowing driven by the Potential difference between the two things leading to a current

Hypothetically if a capacitor and a resistor were in series and the battery is turned on at t = 0; Qc = 0 and V = IR

Over time Vcap = Vbat as the Capacitor fills up with Charge Q = CV; and Vres = 0 as Current goes to zero

Okay so as the capacitor is charging there exists a potential difference between the battery and the capacitor and this allows current to flow through the entire circuit (and thus the resistor) but when the capacitor is fully charged there is no potential difference and no need for current?

 

[onedirection]

Exactly

But that's true only if the capacitor and resistor were in series

If they were in parallel, some current will leave the junction and go to the resistor still

 

[GomerPyle]

Exactly

But that's true only if the capacitor and resistor were in series

If they were in parallel, some current will leave the junction and go to the resistor still

Okay cool, i understand that now. Thanks. And when the capacitor discharges if there was a switch (that left out the battery), the current would flow the opposite way....

 

[brood910]

Exactly

But that's true only if the capacitor and resistor were in series

If they were in parallel, some current will leave the junction and go to the resistor still

BUMP
Im kinda confused about this.
So, I understand that resistors in parallel with capacitor will have the same voltage drop.
And I also know that resistors in series do not give any voltage drops.
But if what you are saying is true, then how is it possible that the resistors in series do not get any current while those in parallel get it when all of them are in the path current travels?