Introduction:
An electric cell is needed in an electric circuit to provide the necessary electrical energy for the circuit to function. It acts as a source of electrical power and supplies a consistent voltage to the circuit components. When multiple cells are joined together, it increases the overall voltage and ensures a stable power supply for the circuit.

Function of an Electric Cell:
An electric cell converts chemical energy into electrical energy. It consists of two electrodes, a positive electrode (cathode) and a negative electrode (anode), immersed in an electrolyte solution. Chemical reactions occur within the cell, causing a flow of electrons from the negative electrode to the positive electrode. This flow of electrons creates an electric current that can be used to power various electrical devices.

Why Join Multiple Cells?
There are several reasons why more than one electric cell may be joined together in a circuit:

1. Increased Voltage: Each electric cell has a specific voltage rating, which is the potential difference between its positive and negative terminals. By connecting cells in series (positive terminal to negative terminal), the voltages add up. This increases the overall voltage supplied to the circuit, allowing it to operate with higher energy and power more demanding devices.

2. Stable Power Supply: Joining multiple cells in parallel (positive terminal to positive terminal and negative terminal to negative terminal) increases the current capacity of the circuit. This ensures a stable power supply as the cells can collectively provide a higher current without getting drained quickly. It is especially useful for devices that require high currents, such as motors or bright light bulbs.

3. Extended Battery Life: By using multiple cells, the total energy capacity of the circuit increases. This means that the circuit can operate for a longer duration without requiring recharging or replacement of cells. It is particularly beneficial for portable devices like mobile phones, where extended battery life is desirable.

In Conclusion:
An electric cell is essential in an electric circuit to provide electrical energy. Joining multiple cells together increases the overall voltage, ensures a stable power supply, and extends the battery life of the circuit. By understanding the functions and advantages of using multiple cells, we can design and construct circuits that meet our specific power requirements.