Q. A radio station has two channels. One is AM at 1020 kHz and the other FM at 89.5 Mhz. For good results you will use
A) Longer antenna for the AM channel and shorter for the FM
B) Shorter antenna for the AM channel and longer for the FM
C) Same length antenna will work for both
D) Information given is not enough to say which one to use for which
Explanation
(a) For efficient radiation and reception, the height of to be the transmitting and receiving antennas should be comparable to a quarter wavelength of the frequency used.
Therefore FM has shorter antenna and AM has longer antenna.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.