What voltage adjustment can be made using taps on a transformer?

Taps on a transformer are used to allow for adjustments to the output voltage to accommodate variations in input voltage. This means that if the input voltage is either lower or higher than the rated voltage, the taps can help optimize the transformer's performance.

In scenarios where the input voltage is lower than the rated voltage, a tap may be used to lower the turns ratio, hence increasing the output voltage to ensure that the load receives the necessary voltage for proper operation. Conversely, if the input voltage is higher than the rated voltage, adjusting the taps can reduce the output voltage, safeguarding the connected equipment from potential damage due to overvoltage conditions.

Hence, the correct understanding is that using taps allows a transformer to adapt to both lower and higher input voltage situations effectively.