Ultra-violet (UV) rays have shorter wavelengths than infra-red (IR) rays. This is correct. In the electromagnetic spectrum: UV → shorter wavelength than visible light Visible light → in the middle IR → longer wavelength than visible light So, UV has a much shorter wavelength than IR. - UV rays produce fluorescence. This is also correct. Ultraviolet rays are well-known for causing certain materials (like fluorescent dyes, whitening agents, or minerals) to glow or emit visible light — this is called fluorescence. It's commonly used in black lights, forensic science, etc.