What are copper loss, iron loss and hysteresis loss in transformer?

Explanation

It consists of a rectantular soft iron core made of laminated sheets well insulated from each other. Two coils PP and SS of insulated copper wires are wound on the same core either on separate limbs of the core or on top of the other. These coils are well insulted from each other. The coil PP to which the source of alternating e.m.f. (to be transformed) is connected is called primary coil and the coil SS from which output electrical energy is drawn is called secondary coil. The secondary coil is wound closed to the primary, so that magnetic flux linked with each turn of the secondary coil is the same as linked with each turn of the primary.
In a step-up transformer, the primary coil PP consists of a few turns of thick insulated copper wire, whereas the secondary coil SS consists of a large number of turns of thin insulated copper wire.
In a step-down transformer, the primary coil PP consists of a large number of turns of fine insulated copper wire, whereas the secondary coil SS consists of a few turns of thick insulated copper wire.
Energy losses in transformer :
1. Copper losses :
2. Iron losses :
3. Hysteresis loss : This is the loss of energy due to repeated magnetisation and demagnetisation of the iron core when alternating current is fed to it. This loss of energy can be minimised by selecting the material of core, which has a narrow hysteresis loop.
Long distance transmission of AC with the help of transformer : For reducing I, a step-up transformer is used at the generating station. Such a transformer, as stated earlier converts electric power, at low voltage and high current to the same power at higher voltage and lower current. If I is sufficiently reduced, `I^(2)R` would be negligible even when R is not very small. It means that we can use thin line wires for transmission in place of thick wires. By doing so, we will be able to save a large amount of material of wire and thus the cost of transmission is reduced. Hence, even if some `I^2` R loss and small amount of IR voltage drop may be there, at the city substation, the transmission ratio `N_(s)"/"N_(p)` of the transformer can be adjusted suitably, so that voltage available for use can always be equal to the original value say, 220V.
Thus a transformer finds a most useful application in long distance transmission of electric power without much wastage.