The Concept of Cell

In a nutshell, a cell is a device that develops electric energy by converting chemical energy. The energy is called current. Cells are used in electrical circuits, and a combination of several cells together forms a battery. Apart from this, a cell can also be described as a source of electricity. The structure and internal resistance of a cell enable it to supply electric power.

Furthermore, the positive terminal of the unit has a higher electric charge than that of the negative terminal. A charge gets potential electrical power from a chemical reaction as it moves throughout the cells from the negative to the positive terminal. The potential difference, or voltage, is the increase in power for every unit (coulomb) of charge. 

Structure and Internal Resistance of a Cell

• Structure

An electric cell constantly converts chemical energy into electric power. It is a standard device with two terminals placed in the middle of the circuit. Its poles are usually made of metal and are denoted as positive and negative terminals. The electricity flows from the cell’s positive terminal to its negative terminal.

• The internal resistance of a cell

Internal resistance refers to the electrical resistance found within the battery and power supply units that could limit the voltage differential available to applied stress. 

An external circuit’s electromotive runs from the cell’s polarity terminals, passing via several circuit parts. A continuous current must travel from the negative pole through the cell’s electrolyte to the positive bar.

In simpler words, the internal resistance of a cell refers to the electrolytes of the cell creating barriers to current flow during that same phase within the cell. These barriers are termed the internal resistance of a cell.

Potential Difference and EMF of a Cell

• Potential difference 

The potential difference can be referred to as the voltage difference, which is developed when electricity moves from one terminal to another terminal. 

The potential difference of a cell can also be described as additional energy required to carry a charge through one end in an electric field to another end. A device called the potentiometer is used to measure this potential difference. 

• Electromotive Force

The electric potential that an electrochemical cell creates by enabling a shift inside the magnetic field is referred to as electromotive force. It is often abbreviated as EMF or ‘E’. Transferring energy between one state to another requires the application of a cell or generator.

Combination of Cells in Series and in Parallel

Like resistors or any other device, a combination of cells can also be placed in a circuit. Also, they can be placed with different arrangements. 

A series arrangement in physics is when a circuit is attached with components in a series. Similarly, a parallel arrangement is when elements are arranged so that they are parallel to each other. 

Let’s discuss more cell combinations in these arrangements. 

• Combination of cells in series

In this arrangement, a negative terminal of the first cell is connected to the positive end of another cell. It is a chain of more than one cell where not a single cell is connected via the same terminal to another.

In case any cells are combined with like terminals, a circuit will be breached, and the current wouldn’t be able to travel through the circuit. It occurs since a current travels from the negative to the positive pole. A similar connection would break this flow by creating conflict in this rule. 

• Combination of cells in parallel

The above image clearly depicts the combination of cells in parallel. A combination of three cells is given between points A and B. Here, all three cells are supposed to be arranged by the positive terminal at the first end and the negative terminals at the other. 

Conclusion

In this article, we looked at the various aspects of electrical cells. A cell is an electrical device that constantly converts chemical energy into electric power in order to keep the flow of electricity functioning. Moreover, this device has two metal ends with a positive and negative charge. Cells are mainly used in electrical circuits. 

We look at the potential differences in internal resistance. Apart from these, we also discussed the combination of cells in series and in parallel arrangements.