When light strikes a photoconductive material, what is generally observed?

When light strikes a photoconductive material, what is generally observed?

• A. Increased resistance
• B. Decreased resistance
• C. No change in resistance
• D. Increased capacitance

Answer: (B)

When light strikes a photoconductive material, it generally leads to a decrease in resistance. This phenomenon occurs because the energy from the light photons excites electrons within the material, promoting them from a bound state to a free state. When more electrons are free to move, the conductivity of the material increases, resulting in decreased resistance. In photoconductive materials, the effect of light is crucial for their operation, especially in devices like photodetectors and image sensors, where changes in resistance due to light exposure are used to generate electrical signals. Understanding this fundamental principle is essential for grasping how photoconductive materials function in various applications.

When light strikes a photoconductive material, it generally leads to a decrease in resistance. This phenomenon occurs because the energy from the light photons excites electrons within the material, promoting them from a bound state to a free state. When more electrons are free to move, the conductivity of the material increases, resulting in decreased resistance.

In photoconductive materials, the effect of light is crucial for their operation, especially in devices like photodetectors and image sensors, where changes in resistance due to light exposure are used to generate electrical signals. Understanding this fundamental principle is essential for grasping how photoconductive materials function in various applications.