Q. The velocity of all radio waves in free space is $3 \times 10^{8}\ m/s$. The frequency of a radio waves of wavelength $150\ m$ is
A) 20 $kHz$
B) 2 $kHz$
C) 2 $MHz$
D) 1 $MHz$
Explanation
(c) Here : Velocity of electromagnetic waves in free space and wavelength
$v = 3 \times 10^{8}m/s$ and $\lambda = 150m$
The frequency of radio waves is given by
$= \frac{v}{\lambda} = \frac{3 \times 10^{8}}{150} = 2 \times 10^{6}\ Hz = 2\ MHz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.