- #1
What is the potential difference between points A and B in a circuit?
- Thread starter kalupahana
- Start date
Click For Summary
Homework Help Overview
The problem involves determining the potential difference between two points, A and B, in a circuit with specified voltages and internal resistances of the cells. The context is rooted in circuit analysis, particularly focusing on the implications of short circuits.
Discussion Character
- Exploratory, Assumption checking, Conceptual clarification
Approaches and Questions Raised
- Participants discuss the implications of a potential short circuit between points A and B, questioning the resulting potential difference. Some explore the relationship between resistance and current in the context of short circuits, while others clarify their reasoning regarding circuit parameters.
Discussion Status
The discussion reflects a mix of interpretations regarding the potential difference, with some participants suggesting that a potential difference of zero is expected in a short circuit scenario. There is acknowledgment of the need to understand the conditions under which this occurs, but no consensus has been reached on the specific calculations or outcomes.
Contextual Notes
Participants are navigating assumptions about the circuit configuration and the definitions of short circuits, with some noting the potential for infinite current in certain conditions. The original poster's attempts at a solution are referenced but not detailed.
- #2
Metaleer
- 123
- 0
AB seems to be a shortcircuit. That is a potential difference of 0, so if you end up getting that, it's nothing to worry about. If you got something other than 0, that's when you should be worried. 
Basically, you can think of a shortcircuit as taking a branch with a single resistor R, and doing R → 0. From V = IR, you see that I = V/R, so if R → 0, the only way to stop I from going to infinity and being a defined finite value, is to have V = 0, that is, the potential difference across a shortcircuit vanishes.
Basically, you can think of a shortcircuit as taking a branch with a single resistor R, and doing R → 0. From V = IR, you see that I = V/R, so if R → 0, the only way to stop I from going to infinity and being a defined finite value, is to have V = 0, that is, the potential difference across a shortcircuit vanishes.
- #3
SammyS
Staff Emeritus
Science Advisor
Homework Helper
- 11,987
- 1,584
If VAB ≠ 0, then it would be I-i that goes to infinity.Metaleer said:AB seems to be a shortcircuit. That is a potential difference of 0, so if you end up getting that, it's nothing to worry about. If you got something other than 0, that's when you should be worried.
Basically, you can think of a shortcircuit as taking a branch with a single resistor R, and doing R → 0. From V = IR, you see that I = V/R, so if R → 0, the only way to stop I from going to infinity and being a defined finite value, is to have V = 0, that is, the potential difference across a shortcircuit vanishes.
- #4
Metaleer
- 123
- 0
The I in my explanation was the I of an arbitrary branch in which a shortcircuit is produced, I didn't use the same circuit as the one given. That's why I said V = IR, and not V = (I-i)R.
The I of my example would be extrapolated to whatever it need be, per particular circuit.
The I of my example would be extrapolated to whatever it need be, per particular circuit.
- #5
kalupahana
- 31
- 0
Ok thanks for help, i got it
- #6
Metaleer
- 123
- 0
You're welcome. 
Similar threads
- · Replies 1 ·
- · Replies 15 ·
- · Replies 2 ·
- · Replies 8 ·
- · Replies 30 ·
- · Replies 4 ·
- · Replies 6 ·