Understanding EMF, Potential Difference & Current Flow

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In summary, electromotive force (emf) is the potential difference that a battery can theoretically maintain when no current is flowing through the circuit or when the circuit is open. This emf is based on the way the battery was built and the chemical reactions that occur inside. However, when the battery is connected to a closed circuit, the movement of ions and the internal resistance of the battery reduces the actual potential difference that can be maintained. This is known as the potential difference and it is a measure of the voltage or energy available to move electrons through the circuit. While emf and potential difference are often used interchangeably, they have slightly different meanings and should be understood in the context of the battery's operation.
  • #1
rahuld.exe
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'it is emf when no current is flowing outside the cell. Whereas, it is potential difference is when current actually flows out of the cell."

"that emf is the potential difference when there is no current flowing through the circuit or when the key is open. Whereas, the circuit has certain value of potential difference when there is current flowing through the circuit."

i read it somewhere n i guess both mean the same... can someone please explain what, how, when, why (basically, everything about it)... in case they don't mean the same thing kindly explain both...
regards
 
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  • #2
The electromotive force is the theoretical maximum value for the potential difference the battery can maintain, based on how it was built.

When you connect the battery to a closed circuit, inside the battery is triggered a chemical reaction that sustain this potential difference. There are ions inside the battery that must move constantly, providing the electrons to go around the circuit. The problem is, this movement of the ions is not instantaneous and electrons are not readily available. This time for the electrons to become available acts somewhat like an internal resistance of the battery. Since the current of ions inside the battery have this internal resistance they must overcome, it reduces the actual potential difference that the battery can maintain when it is connected to a circuit.
 
  • #3
hmm.. that helped.. thanks!
 

1. What is EMF and how does it relate to electricity?

EMF stands for electromotive force and is a measure of the potential difference between two points in a circuit. It is the force that causes charged particles to move, creating an electric current.

2. What is potential difference and how is it different from EMF?

Potential difference, also known as voltage, is the difference in electric potential energy between two points in a circuit. It is measured in volts and represents the amount of work required to move a unit charge from one point to another. While EMF is the total potential difference in a circuit, potential difference refers to the specific difference between two points.

3. How does current flow in a circuit?

Current, measured in amperes, is the rate at which electric charge flows through a circuit. It flows from a higher potential (positive) to a lower potential (negative) and is influenced by the resistance of the circuit components. The flow of current is essential for powering electrical devices and completing circuits.

4. What factors affect the amount of current in a circuit?

The amount of current in a circuit is affected by the voltage (or potential difference) and the resistance of the circuit. A higher voltage will result in a greater current flow, while an increase in resistance will decrease the current. Additionally, the type and size of the conductors and the number and type of circuit components can also affect the amount of current.

5. How can understanding EMF, potential difference, and current flow be useful in everyday life?

Understanding these concepts can help individuals troubleshoot and repair electrical devices, as well as make informed decisions about energy usage and safety. It can also aid in understanding the effects of electromagnetic fields on human health and how to minimize exposure. Additionally, knowledge of EMF and current flow is essential for the design and functioning of many modern technologies and advancements.

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