The answer of this question is B.
Answer:
Wavelength of radio is wave is 3 m
Explanation:
Wavelength of radio is wave is

where

wavelength is

Answer:
Magnetic force, attraction or repulsion that arises between electrically charged particles because of their motion. It is the basic force responsible for such effects as the action of electric motors and the attraction of magnets for iron. Electric forces exist among stationary electric charges; both electric and magnetic forces exist among moving electric charges. The magnetic force between two moving charges may be described as the effect exerted upon either charge by a magnetic field created by the other.