Ultra-violet radiation from sunlight causes a reaction that produces

Ultra-violet light causes

UV radiations form sun causes, which one of the following disorders of eye?

Name the constituent radiation of electromagnetic spectrum which produces intense heating effect.

"Photosynthesis protects us from harmful ultraviolet radiation of sun". Comment on the statement.

What are ultra-violet rays?Give their two uses.

State two applications of ultra-violet radiations.

In pair annihilation, an electron and a positron destroy each other to produce gamma radiation. How is the momentum conserved?