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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: - Two bodies of masses m₁ and m₂ are initially at rest at infinite distance apart
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Topics: Electromagnetic Waves
(28)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Two bodies of masses m₁ and m₂ are initially at rest at infinite distance apart
- When a ceiling fan is switched off its angular velocity reduces to 50% while
- Two identical capacitors each of capacitance 5 mF are charged potentials 2 kV and 1 kV
- A wire of length 1 m is moving at a speed of 2 ms⁻¹ perpendicular to its length
- A sample of HCl gas is placed in an electric field of 5 x 10⁴ N/C
Topics: Electromagnetic Waves (28)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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