| ⇦ | 
| ⇨ |
Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a large irradiated by this beam is:
Options
(a) 3 x 10¹⁶
(b) 9 x 10¹⁵
(c) 3 x 10¹⁹
(d) 9 x 10¹⁷
Correct Answer:
3 x 10¹⁶
Explanation:
λ = 667 x 10⁻⁹ m, P = 9 x 10⁻³ W
P = Nhc / λ, N = no. of photons emitted/sec.
N = (9 x 10⁻³ x 667 x 10⁻⁹) / (6.6 x 10⁻³⁴ x 3 x 10⁸)
= 9 x 6.67 x 10⁻¹⁰ / 3 x 6.6 x 10⁻²⁶
3 x 10¹⁶ / sec
Related Questions: - A light whose frequency is equal to 6.0 x 10¹⁴ Hz is incident on a metal
- The number of photons of wavelength of 540 nm emitted per second by an electric bulb
- The equiconvex lens has focal length f. If it is cut perpendicular to the principal
- Two bulbs when connected in parallel to a source take 60W each, the power consumed,
- The escape velocity from the earth is Ve. The escape velocity from a planet
Topics: Dual Nature of Matter and Radiation
(150)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A light whose frequency is equal to 6.0 x 10¹⁴ Hz is incident on a metal
- The number of photons of wavelength of 540 nm emitted per second by an electric bulb
- The equiconvex lens has focal length f. If it is cut perpendicular to the principal
- Two bulbs when connected in parallel to a source take 60W each, the power consumed,
- The escape velocity from the earth is Ve. The escape velocity from a planet
Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply