Answer:
The efficiency of a transformer is the ratio of its output power to its input power, expressed as a percentage. You can calculate it by dividing the output power by the input power and multiplying by 100%. The formula for efficiency is:
Efficiency = (output power / input power) x 100%
Transformers have losses due to factors such as resistance, core losses, and leakage inductance, which reduce their efficiency. Therefore, the actual efficiency of a transformer is always less than 100%.