Which of the following can cause a drop in water pressure from a well?

An increase in demand for water can significantly contribute to a drop in water pressure from a well. When multiple users draw water simultaneously or when there is a sudden spike in usage, the existing water supply may struggle to keep up with the demand. This increased demand can lead to a temporary depletion of water in the well, resulting in lower pressure as the system works harder to provide adequate flow to the users. The well pump may not be able to maintain the necessary pressure due to the added strain, especially if it is not sized appropriately for the volume of water being demanded.

In contrast, factors such as higher or lower temperatures and electrical consumption do not directly impact the physical dynamics of water pressure in the same way. Water temperature changes, for example, do not influence the pressure; they may affect the density but not the pressure at the wellhead. Therefore, an increase in demand is clearly the most relevant reason for a drop in pressure in this scenario.