Electromagnetic Waves

JEE Main level, single correct, medium

136 of 165

Question 136 of 165

An electromagnetic wave of frequency v=3.0MHzv=3.0 \mathrm{MHz} passes from vacuum into a dielectric medium with permittivity ε=4.0\varepsilon=4.0. Then

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Answer: (C) wavelength is halved and frequency remains unchanged

Refractive index, μ=εε0=2\mu=\sqrt{\frac{\varepsilon}{\varepsilon_0}}=2
Speed and wavelength of wave will becomes half, the frequency remaining unchanged (frequency of a wave depends on the source as due to refraction, it is assumed that the energy is conserved. hv remains the same)

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