An electromagnetic wave of frequency v = 3.0MHz passes from vacuum int...
Given: frequency f = 2MHz, relative
permittivity ∈r= 4
From formula,
velocity
[Since frequency remains unchanged]
View all questions of this test
An electromagnetic wave of frequency v = 3.0MHz passes from vacuum int...
Let's call the relative permittivity of the dielectric medium "εr".
The speed of light in vacuum is approximately 3.00 x 10^8 m/s.
The speed of light in the dielectric medium will be reduced by a factor of √εr, according to the formula:
v = c/√εr
where v is the speed of light in the dielectric medium, c is the speed of light in vacuum, and εr is the relative permittivity of the dielectric medium.
So, the speed of light in the dielectric medium will be:
v = (3.00 x 10^8 m/s) / √εr
The wavelength of the electromagnetic wave will also change as it passes into the dielectric medium. The formula for wavelength is:
λ = c/v
where λ is the wavelength, c is the speed of light in vacuum, and v is the speed of light in the dielectric medium.
So, the wavelength of the electromagnetic wave in the dielectric medium will be:
λ = (3.00 x 10^8 m/s) / [(3.00 x 10^8 m/s) / √εr]
Simplifying this expression:
λ = λ0 / √εr
where λ0 is the wavelength of the electromagnetic wave in vacuum.
Finally, we can calculate the wavelength of the electromagnetic wave in the dielectric medium, knowing its frequency:
v = fλ
where f is the frequency and λ is the wavelength.
So,
λ = v/f = (3.00 x 10^8 m/s) / (3.0 x 10^6 Hz) = 100 m
Therefore, the wavelength of the electromagnetic wave in vacuum is 100 meters.
Using the formula we derived earlier,
λ = λ0 / √εr
we can solve for λ0:
λ0 = λ x √εr = 100 m x √4 = 200 m
Therefore, the wavelength of the electromagnetic wave in the dielectric medium is 200 meters.