A device engineer is tasked with designing a resistive touchscreen interface for a mobile device. It consists of two conductive layers: a flexible upper layer and a rigid lower layer, separated by a narrow gap. The resistance between the two layers is high. Upon touching the screen, the two layers make contact at a point called the touchpoint, reducing the resistance between the layers. To determine the precise touchpoint location, the touchscreen is simplified to a one-dimensional system. The top layer is characterized by its length, resistivity, and cross-sectional area and is divided into two parts at the touchpoint with resistances proportional to their length. If a voltage source is connected between the two ends of the top layer, the circuit resembles a voltage divider circuit, and the voltage drop at the touchpoint depends on these two resistances. Substituting the resistance values and solving the equation gives the relation between the voltage drop at the touchpoint and its position. At each touchpoint, the voltage is distinct, which helps to pinpoint the location accurately.