Uses of transformers :
Transformers are used in electrical appliances which operate at a voltage other than the voltage supplied by the mains.
Step-up transformers are used in :
(i) transmission of electric power at the power generating station.
(ii) television.
(iii) wireless sets, and
(iv) X-ray tubes to provide a high accelerating voltage.
Step-down transformers are used in :
(i) electric bells.
(ii) radio-sets for valve heaters, and
(iii) power sub-stations to step-down the voltage before its distribution to the consumers.
Use of transformers in power transmission
The most important use of transformers is in power transmission over long distances. We can transmit 100 A at 200 V or 1 A at 20,000V or 0.1 A at 200,000 V and in each case the power transmitted is same (= 20,000 W).
But if the transmission is done at a low current say at 0.1A, then the energy loss in the line wires due to heating will be drastically reduced i.e., the transmission losses will be very low. When current is low, we can use thinner wire for transmission and thus can save a lot on the cost of the metal used for wire and huge support needed for the wires. It is for this reason that the voltage of the electricity generated at the generating station is raised up by a step-up transformer before transmitting to other places. At the distribution centre, the voltage is reduced by a step-down transformer and then the electricity is supplied to the consumers.
