How does a resistive touch screen determine the location of a touch?

A resistive touch screen determines the location of a touch by measuring the change in electrical resistance at the point of contact. When pressure is applied, the top layer of the screen (often a flexible conductive layer) touches the bottom layer (usually a rigid conductively coated layer), completing an electrical circuit. The device then calculates the position of the touch based on where that contact occurs, using the change in resistance to identify the coordinates.

The other methods mentioned, such as heat detection or infrared light, are not applicable to resistive touch screens. Heat detection relies on thermal sensing, which is used in different technology types, while infrared systems are characteristic of other types of touch screens like infrared touch screens. Thus, the correct answer focuses specifically on the mechanism of measuring resistance, which is the fundamental principle behind how resistive touch screens work.