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 12
A laser beam has a power of 2 W and a cross-sectional area of 1 mm². Calculate the intensity of the beam in W/m².
A laser emits a beam with a power of 5 mW at a wavelength of 500 nm. Calculate the number of photons emitted per second. (h = 6.626 × 10⁻³⁴ J·s, c = 3.00 × 10⁸ m/s)
A ruby laser emits light at a wavelength of 694.3 nm. Calculate the energy of a single photon emitted by this laser. (Planck's constant h = 6.626 × 10⁻³⁴ J·s, speed of light c = 3.00 × 10⁸ m/s)
Describe the difference between a three-level and a four-level laser system.
Describe the role of the optical resonator (cavity) in a laser.
Explain the term 'population inversion' in the context of lasers.
Explain why a laser beam does not spread out as much as ordinary light.
Explain why lasers are used in optical fiber communication.
Explain why population inversion is necessary for laser action.
State one advantage of using lasers in medical surgery.
State one major difference between spontaneous emission and stimulated emission.
