## Content video: Quize: junction rule and RC circuits

lotus0618
Posts: 182
Joined: Sun Dec 29, 2019 5:47 pm

### Content video: Quize: junction rule and RC circuits

Can someone please explain to me why there would be no current flow out of the battery when it has an open switch? I don't understand teh explaination. What makes sense to me is in presence of a close switch, a current would flow out of the battery. thank you!
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question current flow out of battery.png
NS_Tutor_Mathias
Posts: 616
Joined: Sat Mar 30, 2019 8:39 pm

### Re: Content video: Quize: junction rule and RC circuits

In order for current to flow, you need a potential difference. If I simply don't close the circuit (like an open switch right after a battery - that's really just a wire hanging out, doing nothing), then there is no potential difference and no current will flow. Boring.

The explanation is saying that if the open switch was simply interrupting one of many possible paths, but a path towards the potential difference still exists, then current flow would not be interrupted.

Take this linked image for example:
https://www.dlsweb.rmit.edu.au/Toolbox/ ... ircuit.htm

Ignore the fuse. If the top-most switch is open, no current flows. If the top-most switch is closed, current flows, despite the middle switch being open. If both switches are closed, current still flows (in reality: rather briefly, since this will short out - but the MCAT doesn't care about that).
lotus0618
Posts: 182
Joined: Sun Dec 29, 2019 5:47 pm

awesome!! thanks