Ohm's Law can be applied to a certain extent to analyze the behavior of light-sensitive resistors (LDRs) in automatic light control systems, but it has limitations when dealing with LDRs and similar non-linear components.
Ohm's Law states that the current passing through a conductor between two points is directly proportional to the voltage across the two points, given a constant temperature. Mathematically, it is expressed as:
V = I * R
Where:
V = Voltage across the resistor (in volts)
I = Current flowing through the resistor (in amperes)
R = Resistance of the resistor (in ohms)
LDRs, however, are not linear resistors like most common fixed resistors. Instead, they are light-dependent devices whose resistance varies with the intensity of incident light. When more light falls on the LDR, its resistance decreases, and vice versa.
In automatic light control systems that use LDRs, the relationship between resistance and illumination follows an approximate inverse square law. This means that the resistance changes rapidly at low light levels but tends to stabilize at higher light levels.
While Ohm's Law can be used in certain situations when the LDR is approximately linear over a specific range of illumination levels, it will not accurately predict the LDR's behavior across its entire range. For precise analysis of LDR behavior in automatic light control systems, you would need to use more specialized equations and models that take into account the non-linear nature of LDRs.
In practice, LDRs are often used as part of voltage dividers or in combination with other components in control circuits, and their behavior is empirically determined through experimentation and calibration rather than relying solely on Ohm's Law.