The windings of distribution transformers can be manufactured with various taps to broaden the range of ______________ suitable for a given installation.

• A. Primary amperage
• B. Secondary amperage
• C. Secondary voltage
• D. Primary voltage

Answer: (D)

Taps on transformer windings are used to adjust the voltage ratio by selecting different numbers of turns in the winding. This lets the same transformer be connected to varying nominal primary voltages and still deliver the required secondary voltage. In other words, it broadens the range of primary voltages that are suitable for a given installation because you can choose a primary tap that matches the local supply while keeping the desired output.

Keep in mind that the current capability is set by the transformer's kVA rating and winding insulation, not by the taps. So changing taps changes the voltage compatibility, not the maximum amperage. Secondary taps would adjust the output voltage, but that doesn’t expand the variety of primary voltages you can accommodate in the installation.