How Do You Calculate the EMF of a Cell in a Circuit?

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SUMMARY

The discussion focuses on calculating the electromotive force (EMF) of a cell in a circuit involving resistors in series and parallel configurations. The user initially calculated the total EMF as 4.8V using the formula V=IR, but later realized that this value does not represent the EMF of the battery. The correct approach involves identifying the total resistance in the circuit and applying the appropriate formulas for series and parallel resistors to accurately determine the EMF.

PREREQUISITES
  • Understanding of Ohm's Law (V=IR)
  • Knowledge of series and parallel resistor configurations
  • Ability to analyze circuit diagrams
  • Familiarity with basic electrical concepts such as current and voltage
NEXT STEPS
  • Study the principles of series and parallel circuits in detail
  • Learn how to apply Kirchhoff's laws for circuit analysis
  • Explore the concept of internal resistance in batteries
  • Practice calculating EMF in various circuit configurations
USEFUL FOR

Students studying electrical engineering, hobbyists working on circuit projects, and anyone looking to deepen their understanding of circuit analysis and EMF calculations.

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Finding the EMF of the cell...

first post =)

Homework Statement


Find the EMF of the cell.
(diagram has been uploaded)



Homework Equations


Resistors is series : Rs= R1 + R2 + R3
Resistors in parallel: 1/Rp = 1/R1 + 1/R2 + 1/r3
V=IR

The Attempt at a Solution


Firstly i re-drew the circuit in a more simple form, to see what resistors are in parralel and which ones are in series. I then found the total resistance in the parralel circuit part that contained the 0.2A current. after that i used : V=IR.
My answer still seems incorrect as i got total EMF = 4.8V
 

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oooouftt said:
I then found the total resistance in the parralel circuit part that contained the 0.2A current. after that i used : V=IR.
That would tell you the voltage across that branch (and all parallel branches), but that's not the EMF of the battery.

Show exactly what you did, step by step.
 

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