How much can a booster transformer typically increase the line voltage?

A booster transformer is designed to increase the voltage level in a power distribution system, primarily to enhance the efficiency of power delivery over long distances or to compensate for voltage drop along the line. The typical increase in line voltage that a booster transformer can achieve usually falls within the range of 5% to 10%.

This range is crucial because it allows for improved voltage levels while minimizing the risk of over-voltage conditions that could lead to equipment damage or other issues. In practice, a 5% to 10% increase effectively addresses common voltage drop issues encountered in distribution systems without significantly overloading the system.

The other options, while they suggest possible increases, are less common for standard booster transformers used in typical applications. Increases of more than 10% may not be practical for many applications due to the risk factors mentioned. Therefore, the choice indicating a 5% or 10% increase accurately reflects both the operational capabilities and safety considerations of booster transformers in electrical distribution systems.