Electric Cell/Potentiometer

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The basic gadget to keep an electric flow in a circuit is known as the electric cell. Cells give electric energy through chemical reactions. Fundamentally, the cell has two electrodes called the positive and negative. These electrodes are submerged in the electrolytic solutions. The positive terminal of the cell has a metal cap, and the negative terminal has a flat metal disc. Whenever the positive and the negative terminals are associated with the electrical device, the flow of current begins. The internal reaction occurs in the chemical present inside the cell to produce electricity. The chemicals get completely used up after some time, and the cell can’t create electricity any longer. A group of cells is known as a battery.

Electric Cell

Working of an Electric Cell

When two metal plates are dipped in the same electrolyte solution, electrons develop between them in an electric cell. One metal will lose electrons while the other metal will acquire electrons. A potential gradient in an electric cell is formed between the two metal plates because of the difference in the electron concentration around them. This potential difference will act as a voltage source for the electrical cell. The electrolyte blocks the movement of electrons from the anode to the cathode; only ions are allowed to flow through the electrolyte. Consequently, we can obtain electric flow from the terminals of the battery.

The cell’s chemical energy gets converted into electrical energy, and eventually, the cell stops generating power. In this manner, the battery becomes unfit to produce positive ions because of the depletion of chemicals, and it becomes incapable of producing an electric current.


The potentiometer is a device that dates back to the dawn of electronics development. The potentiometer is a term made up of the word’s potential difference and metering. A potentiometer is essentially a lengthy piece of uniform wire that is connected to a cell. The long wire is split into multiple pieces in the actual pattern, which are then arranged side by side and joined at the ends with a thick metal strip. A variable resistance (rheostat) connected to the circuit can change the current flowing through the wire. For measuring the potential difference, the resistance can be manually modified. The amount of work done in bringing the charge from one point to another point in a circuit is the potential difference between them.

The potentiometer is a device that compares an unknown voltage to a known voltage to determine its value. It may be used to calculate the emf and internal resistance of a cell and compare the emf of different cells. The potentiometer employs the comparative method. In a potentiometer, the reading is more precise.

The basic principle of a potentiometer is that the potential drop across any part of the wire is proportionate to its length if the wire has a uniform cross-sectional area and a uniform current flows through it.

Potentiometer Sensitivity

The sensitivity of a potentiometer refers to how well the potentiometer can detect minor voltage differences. If we increase the length of the potentiometer resistance with the same driver voltage, the length of the resistance per unit voltage increases. As a result, the potentiometer’s sensitivity improves. Correspondingly, the sensitivity of a potentiometer is proportional to the resistance length. When the driver voltage is reduced for a fixed length of potentiometer resistance, the voltage per unit length of resistance is also reduced. Subsequently, the potentiometer’s sensitivity is increased once more. As a result, the potentiometer’s sensitivity is inversely proportional to the driving voltage.


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