What function do transformers serve in load calculations?

Transformers play a critical role in load calculations by changing voltage levels to match supply and load requirements. In an electrical system, it's common for the voltage level from the utility supply to differ from what is required by the equipment or loads. Transformers adjust these voltage levels, stepping them up to higher voltages for efficient long-distance transmission or stepping them down to lower levels suitable for use by end devices.

This capability ensures that electrical appliances and systems receive the appropriate voltage for optimal operation and efficiency, preventing potential damage from incorrect voltage levels. By matching the voltage levels, transformers help to ensure system reliability and performance, making them an essential component in the energy distribution network.

Other functions stated in the choices do not accurately represent the primary role of transformers in load calculations; they do not supply additional power themselves, protect from surges (although surge protectors serve this function), or connect multiple loads in parallel—all of which relate to different aspects of electrical systems.