The electric field associated with an e.m. wave in vacuum is given by

The Electric Field Associated With An Em Wave In Vacuum Physics Question

The electric field associated with an e.m. wave in vacuum is given by E = i 40 cos (kz – 6 x 10⁸ t), where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is:

Options

(a) 2 m⁻¹
(b) 0.5 m⁻¹
(c) 6 m⁻¹
(d) 3 m⁻¹

Correct Answer:

2 m⁻¹

Explanation:

On comparing the given equation to
E = a₀i cos (ωt – kz) ω = 6 x 10⁸ ,
k = 2π / r = ω / c
k = ω / c = 6 x 10⁸ / 3 x 10⁸ = 2 m⁻¹

Related Questions:

  1. Two identical circular coils A and B are kept on a horizontal tube
  2. Two tangent galvanometers A and B have coils of radii 8 cm and 16 cm respectively
  3. A 10 micro farad capacitor is charged to 500 V and then its plates are joined
  4. The r.m.s speed of the molecules of a gas in a vessel is 400 m/s
  5. Which of the following will be σ if Y=2.4 η?

Topics: Electromagnetic Waves (28)
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Your email address will not be published.


*