Question

The velocity of all radio waves in free space is $3\times 10^{8}m/s$. The frequency of a radio wave of wavelength $150m$ is :

• A. 20 kHz
• B. 2 kHz
• C. 2 MHz
• D. 1 MHz

Answer 1

Answer: (C)

Here : Velocity of electromagnetic waves in free space and wavelength
$v=3\times 10^{8}m/s$
$\lambda =150m$
Using the relation for the frequency of radio waves is given by
$=\frac{v}{\lambda }=\frac{3\times 10^8}{150}$
$=2\times 10^{6}Hz=2MHz$