Electric Cells

Dear, it is my joyful duty to be elaborate on the topic - electric cells. As you know that the MyBook Guru is here, let get started. In the middle of 18th century, a man known as Volta placed a cloth soaked with brine solution in the middle of the copper rod and the zinc rod. He realized that current was flowing through the arrangement.
The arrangement was later named as the voltaic cell or electric cell. In which the zinc rod is called the negative electrode, while the copper rod is called the positive electrode.

Electric cells are classified into primary and secondary cells. Primary cells are not rechargeable. They generates low current due to their high resistance caused by some defects. They are irreversible, such cannot be recharge when exhausted. Secondary cells are rechargeable. They generates high current due to their low resistance. They are usually bulky. Examples of primary cells are Daniel cell and Lechanche cell. Examples of secondary cells are nickel accumulator, lead-acid accumulator, and alkaline accumulator.
Dear, these are the defects of primary cells that makes them possess high resistance, which leads to low generation of current. The first one is the local action. Local action occurs due to the presence of impurities on zinc plate and this leads to high resistance causing low currents. Local action can prevented by the amalgamation of mercury on the zinc plate or by using pure zinc rod.
The second defect of primary cell is the polarization. This is also leads to high resistance causing low current, when hydrogen bubbles at the electrode. Polarization can be prevented by using depolarizers. In Daniel cell, copper(ii)tetraoxosulphate(vi) (CuSO4) is the depolarizer, while in the lechanche cell manganese(iv)oxide (MnO2) is the depolarizer.
Note, you must always keep cells in cool and dry places. Let us call it a day. Don't forget to take along your gift (Click).