Question

The frequency of an electromagnetic wave is 3 x ${10}^7$ Hz. Its wavelength is:

• A. 1 m
• B. 10 m
• C. 100 m
• D. 1000 m

Answer 1

The correct option is B 10 m

The relation between frequency and wavelength for an electromagnetic wave is given by:
$\lambda =\frac{c}{\nu }$,
where $\nu$ is the frequency, $\lambda$ is the wavelength and $\text{c}$ is the speed of light.

Here, frequency $(\nu$) = 3 x ${10}^7$ Hz
and speed of light (c) = 3 x ${10}^8$ m/s

So, $\nu =\frac{c}{\lambda }$,

$\nu$ = $\frac{3\times {10}^8\text{m/s}}{3\times {10}^7\text{Hz}}$ = 10 m

Hence, wavelength of the wave is 10 m.