What is Photoresistor? All Questions › Category: Analog Electronics › What is Photoresistor? 0 Vote Up Vote Down chetan shidling asked 4 years ago I need short information. 1 Answers 0 Vote Up Vote Down chetan shidling answered 4 years ago It is also called LDR, light dependent resistor. When the light falls on LDR its resistance decreases. It is a negative temperature coefficient of resistance, as the temperature(light) increases the resistance decreases.