An electric cell has two terminals, one negative and one positive, because, current cannot pass to only one side. It can only travel through two opposite sides.

Introduction:
An electric cell, also known as a battery, consists of two terminals - a positive terminal and a negative terminal. These terminals play a crucial role in the functioning of the cell. In this response, we will explain why an electric cell has two terminals in detail.

Importance of Terminals:
The terminals of an electric cell serve multiple important functions. Let's explore these functions in detail:

1. Electromotive Force (EMF) Generation:
The primary purpose of an electric cell is to generate an electromotive force (EMF). EMF is the driving force that enables the flow of electric current. The positive terminal of the cell has an excess of positive charge, while the negative terminal has an excess of negative charge. This charge imbalance creates the EMF, which pushes the electrons in the circuit from the negative terminal towards the positive terminal.

2. Current Flow:
The terminals of an electric cell act as the points of connection for an external circuit. The positive terminal connects to the positive end of the external circuit, while the negative terminal connects to the negative end. When the circuit is closed, the electrons flow from the negative terminal, through the circuit, and towards the positive terminal. This flow of electrons constitutes the electric current.

3. Chemical Reactions:
Inside the electric cell, various chemical reactions occur to produce the necessary EMF. These reactions take place at the two terminals. The positive terminal, typically made of a metal oxide, undergoes oxidation, releasing electrons and positive ions. The negative terminal, usually made of a metal, undergoes reduction, accepting the released electrons and negative ions. These chemical reactions at the terminals are essential for the continuous generation of the EMF.

4. Voltage Regulation:
The terminals of an electric cell help regulate the voltage supplied to the external circuit. The difference in potential between the positive and negative terminals determines the voltage of the cell. By connecting multiple cells in series, the voltage can be increased, while connecting them in parallel can increase the current capacity. The terminals allow for easy connection and arrangement of cells to achieve the desired voltage and current requirements.

Conclusion:
The presence of two terminals in an electric cell is essential for its functioning. These terminals facilitate the generation of electromotive force, enable the flow of electric current, host chemical reactions, and allow for voltage regulation. Understanding the significance of the terminals helps in comprehending the operation and utility of electric cells.