A laser is a device that can produce:
Correct answer: D. All of the above
- A. Intense beam of light
- B. Coherent beam of light
- C. Monochromatic beam of light
- D. All of the above
Explanation
A laser is a device that produces an intense, coherent, and monochromatic beam (made of rays) of light. Laser light is different from typical light sources as the beam produced is coherent and monochromatic. Coherent refers to the fact that all the light rays in the beam are in phase, i.e., the troughs of all the light waves in the beam line up together, as do all the crests. Laser light is monochromatic, which means all of the light produced by the laser is of a single wavelength.
Last updated
About Dawn of Modern Physics
Classical physics cannot explain blackbody radiation and related observations, leading to Planck’s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
Practise Dawn of Modern Physics
739 free Dawn of Modern Physics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1.5 mW of 400 nm light is directed at a photoelectric cell. If 0.1% of the incident photons produce photoelectrons, the current in the cell is:
1.5 mW of 400 nm light is directed at a photoelectric cell. If 0.1% of the incident photons produce photoelectrons, the current in the cell is:
A 5 watt LED bulb converts 80% of the power into light photons wavelength 660 nm. What is the number of photons emitted from the bulb in one second.
A black body is considered ideal when it:
A body at temperature T radiates heat according to relation: