Which of the following statements about potential transformers is true?

Potential transformers are designed to reduce high voltages to manageable levels that can be safely measured by instruments. This functionality is crucial because it allows for the accurate measurement of voltage in electrical systems, which is especially important for billing purposes in electrical utilities. Accurate measurement is vital for ensuring that consumers are billed correctly based on their actual usage.

In utility applications, potential transformers enable the use of standard voltmeters and other measuring devices that require lower voltage inputs for safe and precise readings. This enhances the reliability of billing and helps maintain trust between consumers and service providers.

The other options do not accurately reflect the role and significance of potential transformers. Their primary function is indeed voltage conversion, but stating they are used only for that purpose overlooks their broader application in maintaining measurement accuracy. While some modern applications may utilize alternative technologies, potential transformers remain essential for certain types of accurate measurement, particularly in billing contexts. Additionally, they are designed specifically to preserve accuracy, contradicting the idea that they decrease the accuracy of electrical readings.