Technical Standards and Safety Authority (TSSA) G3 Practice Exam

In a step-up transformer, the primary function is to increase the voltage from the primary coil to the secondary coil. This is achieved through the principle of electromagnetic induction, where the ratio of turns in the primary coil to the turns in the secondary coil determines the voltage transformation.

When the number of turns in the secondary coil is greater than that in the primary coil, the voltage is stepped up, meaning the secondary voltage is higher than the primary voltage. This is a fundamental characteristic of step-up transformers, which are often used in electric power transmission to increase voltage levels for efficient long-distance transmission.

Consequently, the correct answer indicates that the voltage in the secondary coil is indeed higher than the primary voltage, confirming the purpose of a step-up transformer in electrical systems. The other options do not align with the operational principles of a step-up transformer, as they either understate or fail to recognize the capability of these transformers to elevate voltage levels.