Final answer:
To identify the primary voltage of an overhead transformer, which is essential for safe operation and efficient power transmission, one can look at the printed information on the transformer. The transformer's primary voltage allows for the application of Faraday's law of induction in the design and correct usage of the device.
Step-by-step explanation:
An overhead transformer's primary voltage is an important aspect of its operation and relates to the transmission of electrical power. To distinguish between the primary and secondary windings in a transformer, such as a step-up transformer, you can compare the voltage levels or the number of loops in each coil. The primary voltage is typically printed on the transformer, aiding in identification. As per the transformer equation, the ratio of the secondary to primary voltages is equal to the ratio of the number of loops in their coils. A step-up transformer, specifically, has a primary voltage that is lower than its secondary voltage, and thus, a greater number of loops in the secondary coil.
Furthermore, Faraday's law of induction states that a time-varying magnetic flux through the secondary coil induces an alternating current (AC) output voltage. Hence, for practical use and safety, the primary voltage rating indicates how much voltage can be applied across the primary coil without causing damage or exceeding the design specifications.