Question involving EMF and internal resistance

In summary, the conversation discusses how a cell supplies different currents when connected to different resistances. When connected to a 5 ohm resistance, the current is 2 Ampere, and when connected to a 9 ohm resistance, the current is 1.2 Ampere. The problem then asks for the calculation of the cell's EMF and internal resistance.
  • #1
Anveshan
1
0
A cell supplies a current of 2 Ampere, when it is connected to 5 ohm resistance and supply a current of 1.2 Ampere. If it is connected to resistance of 9 ohm, find EMF(electro motive force) and Internal Resistance
 
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  • #2
Anveshan said:
A cell supplies a current of 2 Ampere, when it is connected to 5 ohm resistance and supplies a current of 1.2 Ampere if it is connected to resistance of 9 ohm. Find EMF(electro motive force) and Internal Resistance

Hi Anveshan, welcome to PF.

This is your first thread, but next time follow the rules of the Forums, please. You need to use the Template provided and show what you know and what you tried in order to solve the problem. I corrected a bit the problem text. So you connect an R1= 5Ω resistance to a cell and measure the current in the loop: it is I1= 2 A. Then you change the resistance, and connect an R2=9Ω resistance to the cell: The current becomes I=1.2 A. Did you mean so?

How do you calculate the current in a loop that contains a cell with emf E and internal resistance r and an outer resistance R?

ehild
 

Related to Question involving EMF and internal resistance

1. What is EMF?

EMF stands for electromotive force, and it is the measure of the energy that is generated by a source, such as a battery or a generator. It is measured in volts (V).

2. How is EMF different from voltage?

EMF and voltage are often used interchangeably, but they are not exactly the same. EMF is the energy generated by a source, while voltage is the potential difference between two points in a circuit. EMF is the energy that is available to do work, while voltage is the force that drives the current in a circuit.

3. What is internal resistance?

Internal resistance is the resistance that is inherent in a source, such as a battery. It is caused by the materials and construction of the source and can affect the flow of current in a circuit. Internal resistance is measured in ohms (Ω).

4. How does internal resistance affect the EMF of a source?

Internal resistance can cause a decrease in the EMF of a source. This is because as current flows through the source, some of the energy is lost due to the resistance. This means that the actual voltage available to do work in the circuit is lower than the EMF of the source.

5. Can internal resistance be reduced?

Internal resistance is inherent in a source and cannot be completely eliminated, but it can be reduced. Using materials with lower resistance and improving the construction of the source can help to decrease the internal resistance. Additionally, using larger and thicker wires in the circuit can also help to reduce the effects of internal resistance.

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