Terminal PD vs EMF: When is PD Greater?

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  • Thread starter Thread starter Himal kharel
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Discussion Overview

The discussion revolves around the conditions under which the terminal potential difference (pd) of a cell is greater than its electromotive force (emf). It explores the definitions and relationships between terminal voltage, emf, and current in both charging and discharging scenarios.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants suggest that the terminal pd exceeds the emf when the cell is charging.
  • One participant clarifies that the emf is the pd across the terminals when no current is drawn, while terminal voltage is the pd when current is drawn.
  • Another participant presents the equations for terminal voltage, indicating that terminal voltage is less than emf when discharging and greater when charging, depending on the current and internal resistance.
  • There is a call for clearer definitions and circumstances regarding the terms used in the discussion.

Areas of Agreement / Disagreement

Participants express differing views on the definitions and conditions under which terminal pd and emf relate, indicating that multiple competing views remain without a consensus.

Contextual Notes

Limitations include the need for clearer definitions of terms and the specific circumstances under which the relationships are being discussed, as well as the dependence on the internal resistance of the cell.

Himal kharel
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when is terminal pd greater than emf ?
 
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You need to explain your terms and circumstances more thoroughly.
 
Terminal pd of a cell exceeds the emf when the cell is charging.
 
Hi, EMF of a cell is the pd across its terminals when no current is drawn from it. Terminal voltage is the PD across a cell when a current is drawn from it. When the circuit drawn current e.m.f is larger than terminal voltage. During charging terminal voltage lags behind the e.m.f.
 
Terminal voltage V=E-Ir , when nod charging. Where,E:EMF of the cell. I:current. r:internal resistance of the cell.
Terminal voltage,V=E+Ir , when charging.
 

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