subject

Lasers

Physics ⇒ Modern Physics

Lasers starts at 11 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Lasers. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 11
A laser emits light at a wavelength of 632.8 nm. Calculate the frequency of the emitted light. (Speed of light c = 3.0 × 108 m/s)
A laser emits light with a photon energy of 2 eV. Calculate the wavelength of the emitted light. (Planck's constant h = 6.63 × 10-34 J·s, c = 3.0 × 108 m/s, 1 eV = 1.6 × 10-19 J)
Describe one medical application of lasers.
Describe the function of the partially reflecting mirror in a laser.
Describe the role of mirrors in a laser cavity.
Explain the difference between spontaneous emission and stimulated emission.
Explain why laser beams can travel long distances without spreading much.
Explain why laser light is considered highly coherent.
Explain why population inversion is necessary for laser action.
List two industrial applications of lasers.
List two methods of pumping used in lasers.
Name two common types of lasers and their active media.
What does the acronym LASER stand for?
What is meant by the term 'metastable state' in the context of lasers?
What is the main difference between a three-level and a four-level laser system?
Which process is responsible for the amplification of light in a laser?
Who is credited with building the first working laser?
A certain laser emits light with a power output of 2.0 W at a wavelength of 400 nm. Calculate the rate at which photons are emitted by the laser. (Planck's constant h = 6.63 × 10-34 J·s, speed of light c = 3.0 × 108 m/s)
A certain laser operates with an active medium that has three energy levels: E1, E2, and E3 (E3 > E2 > E1). If the population of E2 is 2.5 × 1018 atoms/m3 and the population of E1 is 1.0 × 1018 atoms/m3, calculate the population inversion (ΔN) between E2 and E1.
A laser emits a pulse of light with an energy of 5.0 mJ at a wavelength of 500 nm. Calculate the number of photons emitted in the pulse. (Planck's constant h = 6.63 × 10-34 J·s, speed of light c = 3.0 × 108 m/s)