# Confusing Capacitor question

Ok So im confused on Q15a Paper 1 2020, Edexcel A-level. Any help would be appreciated.

Based of this circuit to me it looks as though once the capacitor is charged, current would stop flowing. However the MS shows the charging curve of a capacitor. Why would that be the case, wouldn't it be a capacitor discharge curve as the capacitor charges it takes pd from every other circuit. Also would there be any significance of Y being an integrated circuit. I'm having a hard time understanding the question.

The setup for the question says the capacitor is initially discharged, from inspection of the circuit diagram it should be clear that S1 is initially open and that the capacitor will begin to charge through the resistors in series when S1 is closed.
Original post by Joinedup
The setup for the question says the capacitor is initially discharged, from inspection of the circuit diagram it should be clear that S1 is initially open and that the capacitor will begin to charge through the resistors in series when S1 is closed.

Im just unclear why the p/d of Y would be the same as the capacitor
Y is connected to the top of the capacitor and the bottom of the capacitor is marked 0V

The integrated circuit will probably turn out to be a voltage controlled electronic switch that switches when Y reaches a specific voltage.
Original post by Joinedup
Y is connected to the top of the capacitor and the bottom of the capacitor is marked 0V

The integrated circuit will probably turn out to be a voltage controlled electronic switch that switches when Y reaches a specific voltage.

What does The bottom of the capacitor being market 0V tell us?
Well the graph is marked potential rather than potential difference, it's probably supposed to reduce confusion.
Original post by Joinedup
Well the graph is marked potential rather than potential difference, it's probably supposed to reduce confusion.

Would Electric Potential be different to potential difference?
Original post by FastTempest
Would Electric Potential be different to potential difference?

You could graph the potential difference across the capacitor without knowing where the zero reference is.

Asking about the potential though means you need to work relative to zero.

Maybe it becomes significant in the next section