Why ultra violet radiation not show any diffraction pattern?

Answer 1

Ultraviolet radiation does diffract (show a diffraction pattern.) All electro magnetic radiation will diffract. Even particle radiation will diffract.

Answer 2

Ultraviolet radiation does exhibit diffraction patterns when passing through an obstacle or slit, but they may not be as easily observable as visible light due to the shorter wavelength of ultraviolet radiation. The diffraction patterns of ultraviolet radiation tend to be more widely spaced and harder to detect without specialized equipment.