Why 10V Between Every Point in Circuit Diagram?

Click For Summary

Homework Help Overview

The discussion revolves around a circuit diagram that indicates a consistent voltage of 10V between various points. Participants are questioning the implications of this voltage across different points, particularly in relation to the presence of resistors and the concept of voltage as a difference in potential energy.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are exploring the reasoning behind the stated voltage values, particularly questioning why there is an assertion of 10V between all points despite the presence of resistors. Some are attempting to reconcile their understanding of Ohm's law with the circuit's behavior.

Discussion Status

The discussion is active, with participants expressing confusion and seeking clarification on the voltage measurements. Some have provided insights into the nature of voltage and potential difference, while others are still grappling with the implications of the circuit's configuration.

Contextual Notes

There is a focus on the interpretation of voltage across different points in the circuit, with specific attention to the role of resistors and the definitions of voltage and potential difference. Participants are encouraged to reconsider their assumptions about voltage in the context of the circuit diagram provided.

goomer
Messages
31
Reaction score
0
Please look at the third circuit diagram from the link below

http://www.allaboutcircuits.com/vol_1/chpt_2/7.html

It says that there should be 10V between every point in the diagram. But shouldn't there be a difference in voltage value between points 1 and 2 and points 3 and 4? There's a resistor between points 3 and 4.

My thinking is that if V=IR and there's a resistor between 3 and 4, it should have a different voltage than between points 1 and 2, which doesn't have a resistor between it.

Please explain why I am wrong...
 
Physics news on Phys.org
goomer said:
Please look at the third circuit diagram from the link below

http://www.allaboutcircuits.com/vol_1/chpt_2/7.html

It says that there should be 10V between every point in the diagram. But shouldn't there be a difference in voltage value between points 1 and 2 and points 3 and 4? There's a resistor between points 3 and 4.

My thinking is that if V=IR and there's a resistor between 3 and 4, it should have a different voltage than between points 1 and 2, which doesn't have a resistor between it.

Please explain why I am wrong...

It refers to any points 'before' and 'after' the resistor.
Examples voltage across points 1-4 or 1-6 or 2-5 or 3-6 and any other combinations are equal.
 


Voltage refers to a difference in potential energy across two points. It's essentially work done to move a charge between two points. In an ideal wire, there is nothing present to impede the charge from moving freely. I say ideal as real wires have some electrical resistance (superconducting wires do not).

Anyway, resistors and capacitors change the degree of work needed to move a charge. Resistors make it more difficult for charges to pass through. This creates a potential difference (this term is synonymous with voltage). So the potential energy before the resistor is different from the potential energy after the resistor. Take the difference between these energies and you get the voltage (V = IR).

Hope this helps.
 


goomer said:
It says that there should be 10V between every point in the diagram.

No. Read it again, it doesn't use those exact words it says..

The voltage between points 1 and 6 is 10 volts, coming straight from the battery. However, since points 5 and 4 are common to 6, and points 2 and 3 common to 1, that same 10 volts also exists between these other pairs of points:

Basically it's saying that in the sentence

"The voltage between points 1 and 6 is 10 volts"

you can:

Replace "6" with "5" or "4"

and/or

Replace "1" with "2" or "3".

No other combinations measure 10V. For example if you measure beween 2 and 3 you get zero volts.
 


Oh wow, I can't believe I missed that...thank you so much!
 

Similar threads

  • · Replies 31 ·
2
Replies
31
Views
5K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
Replies
4
Views
3K
  • · Replies 11 ·
Replies
11
Views
1K