Which of the following statements about transformer efficiency is true?

The statement that transformer efficiency typically ranges from 80% to 98% is accurate because transformers are designed to minimize energy losses during operation, which are primarily due to copper losses in the windings and core losses in the transformer core. In practice, well-designed transformers operate with high efficiency, often between these percentages, with many large transformers achieving efficiencies above 95%.

Factors influencing this range include the transformer's size, design materials, and load conditions. Unlike electric motors—which can have variable efficiency depending on the load and design—transformers maintain a relatively stable efficiency across a range of loads, though their maximum efficiency is usually at or near full load. This characteristic plays a crucial role in the effective transmission of electrical power, making transformers a vital component in electrical systems.