Is it true that a no load tap changer can be adjusted while the transformer is energized?

A no load tap changer is designed to be adjusted only when the transformer is de-energized. This is because when the transformer is energized, making adjustments could result in high voltage and current making it unsafe and potentially damaging to the equipment. A no load tap changer allows for voltage regulation by selecting different turns on the winding without any current flowing through it, ensuring that the adjustment can be made without the risk of arcing or damaging components. Therefore, it is not safe or permissible to make adjustments under load, hence the correct answer is that it is false to say a no load tap changer can be adjusted while the transformer is energized.