Understand Switches & Current Flow in Circuits

  • Thread starter Thread starter maccha
  • Start date Start date
  • Tags Tags
    Circuit Switch
Click For Summary

Homework Help Overview

The discussion revolves around understanding current flow in circuits, particularly in relation to switches and capacitors. The original poster expresses confusion about how current behaves when a switch is opened in a parallel circuit with resistors and how this relates to current flowing into a capacitor.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of opening a switch in a parallel circuit and question why current can flow into a capacitor when a switch is open. There are attempts to clarify the roles of components like resistors and capacitors in the circuit.

Discussion Status

Participants are actively engaging with the concepts, with some providing clarifications and diagrams to aid understanding. There is a mix of hypothetical questioning and attempts to explain the behavior of current in different circuit configurations, but no consensus has been reached on the underlying principles.

Contextual Notes

Some participants reference specific circuit diagrams and the behavior of components under certain conditions, indicating a need for visual aids to enhance understanding. The discussion includes hypothetical scenarios that challenge the assumptions about current flow in circuits.

maccha
Messages
49
Reaction score
0
I'm a little confused about current flow/switches in circuits. Let's say two resistors are connected in parallel to a battery- if there is a switch between the two resistors on the negative terminal side, and the switch is opened, current won't flow through the second resistor, right? If current can't flow through there because there's no where for it to go, how come it can flow "into" a capacitor"?
 
Last edited:
Physics news on Phys.org
Could you please show the circuit diagram?

ehild
 
Something like this: http://www.gcsescience.com/Switches-Lamps-Parallel-Circuit.gif

if all other switches are closed but S4 is open, current won't flow through the last resistor, right? I didn't understand why but someone explained that it is because current has nowhere to go. I don't understand why, then, current can flow into a capacitor.
 
Last edited by a moderator:
It is not capacitor but a battery in the picture. The current flows out of the + pole of the battery and back into the negative pole, and can go along the parallel ways through lamps L1 and L2, but if it "chooses" to go across L3 it can not, as the way is broken.

ehild
 
Yeah I know I'm just asking hypothetically?
 
I believe it has something to do with how a capacitor only stores electrons. A capacitor works via the use of two plates; one hooked up to the positive terminal of say a battery and the other to the negative end. The electrons become stored in the plate attached to the negative terminal of the battery until it becomes equal to the voltage of the battery. If there happens to be a resistor, let's say a light bulb, in between the voltage source and the capacitor then the light bulb will light up (because the electrons flow from the battery to the plate in order to charge the plate) but, soon enough, the bulb will go out (because the plate is storing the electrons).
 
a capacitor has a positively and negatively charged plate. One plate has charge flowing into while the other has charge flowing out of it. No current flows through the capacitor -- the charge flowing into it comes from the battery, and the charge flowing out of it comes from one of the previously neutral plates of the capacitor(leaving an effective charge due to holes).
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
2K
Replies
20
Views
2K
  • · Replies 6 ·
Replies
6
Views
1K
Replies
14
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
Replies
2
Views
1K
Replies
6
Views
1K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 62 ·
3
Replies
62
Views
6K