Why is potential difference the same across each branch in parallel?

Click For Summary

Discussion Overview

The discussion centers on the concept of potential difference in parallel circuits, specifically addressing why two lamps connected in parallel to a 3V battery both receive the same voltage. Participants explore analogies and explanations to clarify this concept.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about how two lamps in parallel can both receive 3V from a 3V battery, questioning the additive nature of voltage.
  • Another participant explains that in a standard circuit diagram, straight lines represent equipotentials, indicating that both lamps share the same potential difference.
  • A participant suggests that the concept of electric potential may be confusing for many students, indicating a broader misunderstanding of the topic.
  • One participant uses a fluid analogy to explain that potential difference across conductors in parallel is not additive, similar to pressure differences in fluid flow.
  • Another participant mentions that all consumer elements in a car experience the same voltage from the battery, reinforcing the idea that parallel components do not affect each other's voltage.
  • Some participants express ongoing confusion about the concept, indicating that the explanations provided have not fully clarified the issue for them.

Areas of Agreement / Disagreement

Participants generally agree on the principle that components in parallel share the same potential difference, but there is significant confusion and lack of understanding among some participants regarding the implications and details of this concept.

Contextual Notes

Some participants may be conflating voltage with current, which could contribute to their confusion about the behavior of parallel circuits.

aidandv
Messages
14
Reaction score
2
As the title says, i am struggling to understand how if the cell is only supplying 3V how 2 lamps in parallel both receive 3 volts (totalling 6)

I currently study a level physics and never really questioned how this works and just accepted it as the truth.

Can someone explain with a helpful analogy?
thank you
 
Physics news on Phys.org
In the standard circuit diagram, each lamp is connected to the battery with a straight lines and there are no other circuit elements between the lamps the battery terminals. Straight lines are equipotentials. Thus the potential has the same value ##V_1## on one side of both lamps and the same value ##V_2## on the other side of both lamps. That means that the lamps are in parallel.
 
  • Like
Likes   Reactions: DeBangis21
The analogies presented in this video may help you understand.

Sorry I had a bad link when initially posting.
 
scottdave said:
The analogies presented in this video may help you understand.

Sorry I had a bad link when initially posting.

Hi is there a specific timestamp for my question?
 
  • Skeptical
Likes   Reactions: Motore
kuruman said:
In the standard circuit diagram, each lamp is connected to the battery with a straight lines and there are no other circuit elements between the lamps the battery terminals. Straight lines are equipotentials. Thus the potential has the same value ##V_1## on one side of both lamps and the same value ##V_2## on the other side of both lamps. That means that the lamps are in parallel.
So what youre saying is in parallel both components have the same potential for charge carriers to do work so theyre the same?
 
I am saying that two conductors in parallel have the same potential difference across their ends.
 
kuruman said:
I am saying that two conductors in parallel have the same potential difference across their ends.
i dont quite understand what this means
 
aidandv said:
i dont quite understand what this means
All the consumer elements in a car "feel" the 12 volts delivered by the car battery.
They are all in parallel to each other and having one consuming electricity does not affect what the other one is receiving.

parallel-circuit.gif
 
aidandv said:
Hi is there a specific timestamp for my question?
So this addresses the concept of electric potential, rather than parallel circuits in particular. I think many students get confused on electric potential. There was another video that I was looking for concerning series and parallel circuits, but I haven't located it yet.
 
  • #10
aidandv said:
As the title says, i am struggling to understand how if the cell is only supplying 3V how 2 lamps in parallel both receive 3 volts (totalling 6)
I think I see now what you mean. Here is the fluid analogy for a circuit. The potential difference across two conductors is analogous to the pressure difference across the constrictions. When you have two constrictions in parallel (bottom drawing taken from the link) the pressure difference between the ends is not additive. Likewise, if the potential difference (think of it as the pressure driving the flow of charge carriers) is not additive. In parallel conductors the currents are additive not the potential differences.

Screen Shot 2023-09-17 at 2.22.39 PM.png
 
  • Like
Likes   Reactions: topsquark, Lnewqban and scottdave
  • #11
I must be really dumb or smth bc I’m still not understanding. It’s ok tho dont worry about it
 
  • #12
You may
aidandv said:
I must be really dumb or smth bc I’m still not understanding. It’s ok tho dont worry about it
You may be confusing voltage with current.
 
  • Like
Likes   Reactions: topsquark

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
5K
  • · Replies 4 ·
Replies
4
Views
23K
  • · Replies 28 ·
Replies
28
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
7
Views
1K
  • · Replies 5 ·
Replies
5
Views
4K
Replies
7
Views
3K
  • · Replies 24 ·
Replies
24
Views
6K