LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are ...

The two diagrams above are of the same circuit for a simple night light. How it works : when darkness falls on the light dependant resistor (LDR), its resistance increases causing a higher voltage ...

National 5; Practical electrical and electronic circuits Process devices. Measurement and analysis of current and voltage in simple circuits allows us to formulate rules and predict unknown values.