The frequency of an electromagnetic wave is 3 | vedclass

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Question

(C) When an electromagnetic wave travels from one medium to another,its frequency $(f)$ remains constant because it depends on the source of the wave.

Vedclass · Accepted Answer

$\lambda$ becomes one-fourth,$f$ remains constant.

Vedclass · Answer

(C) When an electromagnetic wave travels from one medium to another,its frequency $(f)$ remains constant because it depends on the source of the wave.However,the speed of the wave $(v)$ changes according to the refractive index $(n)$ of the medium,where $v = c/n$.Since the speed of the wave is given by $v = f \lambda$,and $f$ is constant,the wavelength $(\lambda)$ changes as $\lambda' = v/f = (c/n)/f = \lambda/n$.Given $n = 4$,the new wavelength $\lambda' = \lambda/4$,which means the wavelength becomes one-fourth of its original value.Therefore,the correct option is $C$.

The frequency of an electromagnetic wave is $3 \, MHz$. If the refractive index of the medium is $n = 4$,what happens to the wavelength and frequency when it passes through the medium?

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