In this blog we are going to tell you about Distinguish between EMF and Potential Difference, so read this blog carefully to get the complete information.
Have you ever worked with batteries and cells in real life? You must have noticed two different potential differences between the terminals of the batteries. These different values are known as EMF and the potential difference of a cell. These potential differences are caused due to the non-ideal nature of the battery which increases the resistance in the battery. Do you also want to know why this phenomenon occurs? If yes then let us understand the concept of EMF and potential differences along with the major differences so that you can identify them and measure them correctly.
What is EMF?
EMF is also known as the electromotive force of a cell. It is the energy that is delivered to the unit charge by the cell. Unlike its name, EMF is not a force at all as it is the potential difference. In other words, we can say that EMF is the potential difference that occurs when no current is flowing in the system. Even though EMF is directly related to the potential difference produced, it is still different from the actual potential difference which is reflected on the terminals of the battery because the terminal voltage is usually less than the EMF of the battery.
What is the Potential Difference?
The voltage output of a battery is measured by its terminals and is called terminal voltage. Usually, the battery is connected to another external resistance in series and there occurs net voltage across the terminals of the battery. The equation form is given by V = EMF – Ir. In this equation, ‘I’ is the current which is flowing through the circuit and r is the internal resistance. So the more the current the lower will be the terminal voltage of the battery. Moreover the smaller the internal resistance the greater the terminal voltage.
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Major Differences between EMF and Potential Difference
The following are the major difference points between EMF and potential difference:
- An EMF is a difference in the potential of two electrodes of a battery whereas a potential difference is the difference of potential between any two points in a given circuit.
- EMF is always greater than the potential difference between the points in the circuit whereas the potential difference is always less than the EMF.
- The formula to calculate EMF is E = I(R+r) while the formula for calculating potential difference is V= IR.
- An EMF can be caused by the electric, gravitational and magnetic fields but the potential difference is only produced by the electric field.
- The electromotive force is the amount of energy that is given to each coulomb of charge whereas the potential difference is the amount of energy that is used by 1 coulomb of charge.
- EMF is independent of the internal resistance of the circuit whereas the potential difference is proportional to the resistance of the circuit.
- Electromotive force is responsible for transferring energy across the circuit whereas the potential difference between any two places on the circuit is only a measure of energy.
- When the circuit is unchanged, the magnitude of electromotive force is always greater than the potential difference while when the circuit has completely changed the size of the potential difference is equal to the EMF of the circuit.
- An electromotive force can be measured using an EMF meter while the potential difference is measured with a voltmeter.
The bottom line
So overall both EMF and potential difference are difference in potential but they are quite different from each other. The difference is that EMF is the difference between the potential of two electrodes of a battery whereas the potential difference is the difference between any two points in the circuit. We hope that this article was helpful and you understood the concept and difference between EMF and potential difference.
Conclusion
We Hope this blog is sufficient enough to provide the information about Distinguish between EMF and Potential Difference. Thanks for reading this blog.
