What is an electric transformer? Explain the main components of the transformer?

An electrical transformer is a static electrical device that can be used to step up and step down the electric current and voltage without changing the frequency.

The major components of an electric transformer are: 

1. Main tank: this is a huge hollow from inside structure, filled with naphtha oil, which inboxes all the components of the transformer.
2. Conservation tank: also known as the expansion tank. It is connected to the main tank and is half filled with naphtha oil.
3. Core: Winded piece of polished soft iron plates to prevent the gap.
4. Winding: generally made of copper wire. They are done in two layers with an insulative paper in between them. The outermost layer is called the primary layer and the inner one is called the secondary one.
5. Naphtha Oil: This is a thick mineral oil that reduces the empty space in the main tank, and prevents the generation of eddy current. 
6. Breather: as the air gets in to maintain the pressure, moisture and dust are also absorbed. To prevent this silica gel is used, which absorbs ith moisture in it, and an oil type dust filter is placed in the entry head of the breather. It is placed on top of the conservation tank.
7. Buchholz relay: To prevent the transformer from blasting off, an automatic mercury-operated switch is placed. This system does not need a power supply and operates on the heat produced by the transformer itself. It is located between the main tank and the conservation tank.
8. Explosion vent: if the Buchholz relay fails to stop the transformer, an elongated pipe with a comparatively weak seal is extended out of the main tank whose opening is higher than the expansion tank, which explodes off. In present days, they are not in use. 
9. Radiator: a mesh made of thin pipes are placed on both sides of the main tank so as to radiate the heat.
10. Terminals: These are of two types, the main supply is high bushing and distribution channel low bushing.