Which equation is correct for EMF: V-Ir or V=EMF-Ir?

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SUMMARY

The correct equation for electromotive force (EMF) is V = EMF - Ir, where V represents the terminal voltage, EMF is the electromotive force, I is the current, and r is the internal resistance. This equation clarifies that the terminal voltage (V) is less than the EMF due to the voltage drop across the internal resistance of the circuit. Understanding this relationship is crucial for accurately analyzing circuits involving internal resistance.

PREREQUISITES
  • Understanding of basic electrical concepts, including voltage, current, and resistance.
  • Familiarity with Ohm's Law and its applications in circuit analysis.
  • Knowledge of electromotive force (EMF) and its significance in electrical circuits.
  • Basic grasp of internal resistance and its impact on circuit performance.
NEXT STEPS
  • Study the implications of internal resistance in real-world circuits.
  • Learn about the applications of EMF in different types of electrical devices.
  • Explore advanced circuit analysis techniques, including Thevenin's and Norton's theorems.
  • Investigate the role of EMF in renewable energy systems, such as solar panels and batteries.
USEFUL FOR

Students studying physics, electrical engineers, and anyone involved in circuit design or analysis who needs to understand the relationship between EMF, voltage, and internal resistance.

RoryP
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was just reading through my physics revision book when i noticed one of the equations for E.M.F
In class and the exams I am sure we used EMF= V-Ir, but the book said that V=EMF-Ir.
was just wondering which one was right so that i don't make a mistake in the future!
any help would be great!
 
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ignore that one guys, i just thought through it and it is V=EMF-Ir.
it has to be because the EMF is the maximum potential difference between 2 electrodes and the voltage is smaller than the EMF due to internal resistance!
 

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