Electric Cell And Its Types

Electric cells are a common source of electric energy for many equipment. Electric cells are used in transistors, calculators, wristwatches, remotes, toys, clocks, cameras, video games, etc. An electrochemical cell is a device which by converting chemical energy into electrical energy maintains the flow of charge in a circuit. It usually consists of two electrodes of different materials and an electrolyte. The electrode at higher potential is called anode and the one at lower potential is cathode

Primary Cells: The cells which cannot be recharged electrically are called primary cells. Here the original state of cell cannot be brought back by passing electrical energy through cell from external source after cell is discharged. the examples are Voltaic cell, Daniel cell, Leclanche cell, manganese-alkaline cell, mercury button cell etc.

Secondary Cells: The cells in which chemical process is reversible are called secondary cells. Here original chemical state of the cell can be brought back by passing electrical energy through cell from external source. The examples are Lead acid accumulator, alkali cells etc.

Advantages of Electric Cells:

1. Electric cells are light so they are portable (can be carried easily).

2. They produce a very small amount of electricity so they are perfectly safe and one can handle them without receiving electric shocks.

3. They are not very costly.

4. They do not contain any liquid chemicals that can be spilled.

5. They supply a steady electric current.

Types of Electric Cells:

Voltaic Cell: This consists of a glass vessel, with dilute sulphuric acid Two plates one made up of copper and the other made of zinc, are placed in the jar such that each one of them is immersed in the acid. When these plates are externally connected to a bulb, electricity flows through the bulb and it glows. The dilute sulphuric acid is called electrolyte. The copper plate acts as a positive pole and the zinc plate acts as a negative pole and in the external circuit electricity flows from the copper plate to the zinc plate.

Leclanché Cell: The Leclanché cell consists of a porous pot and a zinc rod placed in a solution of ammonium chloride solution in a glass jar.The porous pot contains powdered carbon and manganese dioxide with a carbon rod dipped into it. Zinc rod acts as the negative plate and carbon rod acts as the positive plate. Electromotive force of this cell is 1.46 volt.

Dry Cell: This is a modified form of Leclanché cell. This consists of a cylindrical zinc container with a chemical mixture of ammonium chloride, zinc chloride with manganese dioxide and powdered carbon present in the form of a paste. In the middle of this can, there is a carbon rod with a brass cap.The brass cap of the carbon rod and the zinc can act as the positive and negative poles of the cell, respectively. The e.m.f of a dry cell is 1.46 volt.

The Bichromate Cell: This cell consists of a flat bottomed glass flask with a special stopper. A solution of potassium dichromate and dilute sulphuric acid is used as an electrolyte. Two carbon plates act as the positive poles and the zinc plate act as the negative pole. The zinc plate fixed to the stopper can be moved up and down. When the cell is not in use, the zinc plate is placed above the electrolyte. The hydrogen produced in the reaction gets oxidized by potassium bichromate. The e.m.f of this cell is 2 volt.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

In which of the following devices electric cells are used?
A. Calculators	B. Wrist watches	C. Remotes	D. All of these
Right Option : D
View Explanation

Question : 2

Cells can be divided into two categories depending on __________________.
A. Recharging capacity	B. Chemical used	C. Presence of coverings	D. None of the above
Right Option : A
View Explanation