The correct answer is: A. LDR
A photoemissive cell is a type of light-sensitive device that converts light into an electrical signal. The most common type of photoemissive cell is the photodiode, which is a semiconductor device that uses the photoelectric effect to generate an electric current when light strikes its surface.
A photodiode is a semiconductor device that converts light into an electrical signal. It is a two-terminal device, with the anode and cathode terminals connected to an external circuit. When light strikes the photodiode, it creates an electron-hole pair in the semiconductor material. The electrons are then attracted to the anode, while the holes are attracted to the cathode. This creates a current that can be amplified and used to detect or measure light.
Photodiodes are used in a variety of applications, including light sensors, optical communication, and solar cells. They are also used in photolithography, a process used to create patterns on semiconductor wafers.
LDR stands for Light Dependent Resistor. It is a type of photoresistor that changes its resistance in response to light. LDRs are used in a variety of applications, including light sensors, automatic door openers, and burglar alarms.
Phototransistors are a type of transistor that is sensitive to light. They are used in a variety of applications, including light sensors, optical communication, and solar cells.
Photomultipliers are a type of vacuum tube that amplifies light signals. They are used in a variety of applications, including astronomy, spectroscopy, and medical imaging.