What does the efficiency of a transformer indicate?

• A. How quickly it operates
• B. How much power is converted to output power
• C. How many turns are in the winding
• D. How well it manages heat

Answer: (B)

The efficiency of a transformer is defined as the ratio of the output power to the input power, usually expressed as a percentage. It effectively indicates how much of the input electrical power is successfully converted into usable output power without being lost as heat or other forms of energy. In an ideal transformer, the efficiency would be 100%, meaning all input power is transformed into output power. However, in practical applications, some energy is lost due to resistance in the windings, core losses, and other factors, which is why efficiency is always less than 100%. Therefore, option B accurately reflects the concept of transformer efficiency in terms of power conversion.