# The transformer ratings are usually expressed in terms of

The transformer ratings are usually expressed in terms of

### Right Answer is:

KVA

#### SOLUTION

The rating of any electrical machine shows its ability to carry the mechanical load without showing any signs of overheating. **The transformer ratings are usually expressed in terms of KVA.**

There are two types of losses in a transformer

⇒ Iron Losses

⇒ Copper loss

**Copper losses ( I²R)**depends on the**Current**which passes through transformer winding.**Iron Losses (Core Losses or Insulation Losses)**depends on**Voltage**.- This shows that the iron and copper losses depend only on the supply voltage and the current flowing through the winding respectively.
- Since the power factor is dependent on the load which is not stable.
**Since these losses do not depend on the phase angle between the supply voltage and the current, the transformer rating expressed as a product of voltage and current is called the VA rating of the transformer.**- KVA tells you the
*current rating*of the transformer, regardless of the power factor of the load. - Hence, total transformer loss depends on volt-ampere (VA) and not on phase angle between voltage and current

Therefore, the transformer rating is expressed as kVA and not as kW.