Which statement correctly identifies the transformer voltage relationship described as 7200 to 4160 V?

Which statement correctly identifies the transformer voltage relationship described as 7200 to 4160 V?

• A. 7200 to 4160 V is the output-to-input ratio
• B. 4160 to 7200 V is the output-to-input ratio
• C. 2400 to 4160 V is the output-to-input ratio
• D. 7200 to 2400 V is the output-to-input ratio

Answer: (A)

A transformer’s voltage relationship is read as the primary (input) voltage to the secondary (output) voltage. When you see 7200 to 4160 V, it means the device is fed with 7200 V and produces 4160 V on the output, i.e., a step-down. The ratio from input to output is 7200:4160. If you were to express the output-to-input ratio, you’d reverse it to 4160:7200 V. So the given pair describes the input-to-output relationship, not the output-to-input relationship. The step-down factor is 7200/4160 ≈ 1.73, with current increasing on the output side (ignoring losses).

A transformer’s voltage relationship is read as the primary (input) voltage to the secondary (output) voltage. When you see 7200 to 4160 V, it means the device is fed with 7200 V and produces 4160 V on the output, i.e., a step-down. The ratio from input to output is 7200:4160. If you were to express the output-to-input ratio, you’d reverse it to 4160:7200 V. So the given pair describes the input-to-output relationship, not the output-to-input relationship. The step-down factor is 7200/4160 ≈ 1.73, with current increasing on the output side (ignoring losses).