A photoconductive material in irradiation detectors converts which form to an electrical signal?

• A. X-rays into an electrical signal
• B. Electrons into sound waves
• C. Light into an electrical signal
• D. Rays into light

Answer: (A)

Photoconductive detectors convert absorbed photon energy into charge carriers, changing the material’s conductivity and producing a current that can be read as an electrical signal. In irradiation detectors, X-ray photons interact with the photoconductive material to generate electron-hole pairs; under an applied bias, these carriers create a measurable current proportional to the X-ray exposure. This is the direct way X-ray energy becomes an electrical signal.

The other ideas don’t fit this context: converting electrons into sound isn’t how photoconductors detect radiation, and converting light (visible) into a signal would apply to detectors tuned to visible light rather than X-rays. “Rays into light” would describe a scintillator-based indirect conversion, not a direct photoconductor.