Which factor influences an LDR's resistance?

The correct answer is light intensity, as it directly affects the resistance of a light-dependent resistor (LDR). An LDR is a type of resistor that changes its resistance based on the amount of light that hits it. When the light intensity increases, the resistance of the LDR decreases, allowing more electric current to pass through. Conversely, in low-light conditions, the resistance of the LDR increases, resulting in less current flow. This property makes LDRs useful in applications such as automatic lighting systems and light meters, where they can respond to varying light conditions.

Other factors like magnetic fields, temperature, and electrical current do not influence the operation of an LDR in the same direct manner. While temperature can affect the general performance of electronic components, it is not the primary factor for LDR operation. Electrical current might vary based on the LDR's resistance but does not influence the resistance itself. Therefore, light intensity is the key factor driving the functionality of an LDR.