Question

Which one of the following statements is incorrect about laser?

• A. It is a technique for producing intense beams of visible light, ultraviolet or infrared radiation of different wavelengths.
• B. Laser beam can drill a hole, even in diamond.
• C. A variety of lasers have been made from solids like the ruby crystal semiconducting materials, liquids and gases.
• D. All waves in laser travel in different phases.

Answer 1

The correct option is D All waves in laser travel in different phases.

A laser produces a very narrow beam of light that is useful in many technologies and instruments. The laser's light waves travel together with their peaks all lined up, or in phase, because of this the laser beams are very narrow, very bright, and can be focused into a very tiny spot.