Q. How long is the Marriage License valid?A. A Marriage License is valid for 60 days, beginning the day after it is issued. Members of the armed forces who can prove they are on active duty at the time of applying for the Marriage License can obtain a Marriage License valid for 180 days.
Lesson Summary. UV light is one type of electromagnetic wave. Other electromagnetic waves include radio waves, microwaves, visible light, and X-rays. UV light is used by humans to produce vitamin D, but overexposure to UV light can damage DNA and cause painful sunburns, cataracts, and skin cancer.
Xenon is used in certain specialised light sources. It produces a beautiful blue glow when excited by an electrical discharge. Xenon lamps have applications as high-speed electronic flash bulbs used by photographers, sunbed lamps and bactericidal lamps used in food preparation and processing. Xenon lamps are also used in ruby lasers.