Function of a Battery in Simple Circuits

  • Context: Undergrad 
  • Thread starter Thread starter Bheshaj
  • Start date Start date
  • Tags Tags
    Battery Function
Click For Summary

Discussion Overview

The discussion revolves around the function of a battery in simple circuits, focusing on concepts such as electric fields, potential difference, and the movement of charge. Participants explore theoretical and conceptual aspects of how batteries interact with resistors and the resulting electric fields in circuits.

Discussion Character

  • Conceptual clarification
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants inquire about the direction of the electric field in a circuit with a battery and resistors, questioning the meaning of potential difference and the movement of positive charge.
  • One participant emphasizes the importance of showing prior efforts to understand the concepts, suggesting that others can provide guidance based on those efforts.
  • A participant explains potential difference as analogous to gravitational potential energy, discussing how voltage relates to electric fields and the forces acting on charged particles.
  • Another participant introduces the idea of idealization in circuit theory, describing a battery as a device that maintains a defined potential difference regardless of current flow, and compares this to a fluid analogy involving pressure in pipes.
  • Participants also note that realistic batteries operate based on chemical processes, which can affect the potential difference over time as the battery discharges.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the concepts discussed, and there is no consensus on the interpretations of potential difference and electric fields. Multiple viewpoints and analogies are presented without resolution of disagreements.

Contextual Notes

Some limitations include the dependence on idealized models versus realistic battery behavior, as well as the varying interpretations of potential difference and electric fields in the context of circuit theory.

Bheshaj
Messages
20
Reaction score
0
In a simple circuit with battery connected to a resistor or a combination of resistors where is the electric field directed . What do we mean when we say battery creates a potential difference between two points in a conductor? And by the statement that battery moves positive charge from low potential to higher potential?
 
Physics news on Phys.org
Bheshaj said:
In a simple circuit with battery connected to a resistor or a combination of resistors where is the electric field directed . What do we mean when we say battery creates a potential difference between two points in a conductor? And by the statement that battery moves positive charge from low potential to higher potential?
what have you done so far to try and find some answers ?
show your effort and people here will guide you :smile:
 
  • Like
Likes   Reactions: berkeman
davenn said:
what have you done so far to try and find some answers ?
show your effort and people here will guide you :smile:
Please help me. I am not understanding, these statements are directly said by people and written in books tried a lot to find out their meaning. .What do they mean when they say we apply a potential difference. There should be an electric field right to move charges how and where is it directed in a battery and in wires and resistors connected to the battery?
 
Potential difference is a reference to voltage, which is the electrical potential energy per unit (positive) charge. As a crude analogy, it's similar to gravitational potential energy per unit mass (I'm not aware of a term for gravitational potential).

Consider the case of a constant intensity field, which can be approximated by the inner part of a field between two charged plates (such as a capacitor), with a positively charged particle within that field. The voltage is greatest at the more positively charged plate, and zero at the more negatively charged plate. A positively charged particle would experience a constant force towards the more negatively charged plate.
 
  • Like
Likes   Reactions: Bheshaj
The preferred way of working problems with circuit diagrams is to ignore the real-world aspects of the situation and consider the circuit elements as idealizations. They have certain behavior, because they are defined to.

Idealization: A battery is a device that will impose a defined potential difference between its terminals regardless of how much current passes through it. The current can pass through in either direction.

Analogy: If your intuition balks at the idea of abstractions like this, the fluid analogy may be helpful. Potential (voltage) is like pressure in a pipe. A battery is like a pump that imposes a pressure difference. Normally, it does this by pumping fluid received on the low pressure end out to the high pressure end. It imposes the same pressure difference regardless of the flow rate. Negative flow rates are possible -- if the fluid is driven from elsewhere, the pump can absorb energy from the flow like a turbine.

Realistic: A realistic battery operates based on chemistry. Current flows as the battery's chemical stockpile is used up, slowly reducing the potential that the battery is able to provide. A reverse flow allows the chemical stockpile to be restored -- recharging the battery.

In idealized circuit theory one assumes an infinite chemical stockpile with no reduction in voltage as current continues to flow.
 
Last edited:
  • Like
Likes   Reactions: Bheshaj and vanhees71

Similar threads

  • · Replies 21 ·
Replies
21
Views
4K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 14 ·
Replies
14
Views
6K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
5K
  • · Replies 22 ·
Replies
22
Views
7K
  • · Replies 7 ·
Replies
7
Views
2K