What happens to a motor as the fan's adjustable pulley is set to increase speed?

When the fan's adjustable pulley is set to increase speed, the resistance against which the motor must work also increases. This can lead to a situation where the motor has to draw more current to maintain the higher speed. If the increase in speed is beyond the motor's capability, it can result in an overload condition.

An overloaded motor operates at higher temperatures, which can lead to insulation breakdown and ultimately motor failure. Therefore, the correct answer highlights the potential risks involved with increasing the speed too much. Motors have a designed operational capacity, and exceeding that can strain the system and cause damage.

While it’s true that increasing speed can enhance cooling efficiency and speed up the cooling mechanism, these benefits must be balanced against the risk of overloading the motor. If the system is not designed to handle such increases in speed, these benefits become moot, emphasizing the importance of proper system design and motor ratings.