MediumPhysics
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The frequency of an electromagnetic wave in free space is 2 MHz. When it passes through a medium of relative permittivity 4.0, then its wavelength
A
Is doubled
B
Is halved
C
Remains same
D
Becomes four times
Explanation
Speed of light in a medium v = c/√(μrεr). Assuming μr ≈ 1, v = c/√εr = c/√4 = c/2. Wavelength λ = v/f. Since the frequency f remains constant when moving between media and speed is halved, the wavelength is also halved.
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