Monochromatic light of wavelength 667 nm is produced by a helium neon laser

Monochromatic Light Of Wavelength 667 Nm Is Produced By A Physics Question

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:

  1. A conductor of length 5 cm is moved parallel to itself with a speed of 2 m/s,
  2. The interferance pattern is obtained with two coherent light sources of intensity
  3. An electric kettle takes 4A current at 220 V. How much time will it take to boil 1 kg
  4. A body of mass 4 kg is accelerated upon by a constant force travels
  5. The mirrors are inclined at an angle of 50⁰. The number of images formed for an object

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.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*