Question -
Answer -
Distance between the towers,┬аd┬а= 40 km
Height ofthe line joining the hills,┬аd┬а=50 m.
Thus, theradial spread of the radio waves should not exceed 50 km.
Since thehill is located halfway between the towers, FresnelтАЩs distance can be obtainedas:
ZP┬а=20 km = 2 ├Ч 104┬аm
Aperturecan be taken as:
a┬а=┬аd┬а= 50 m
FresnelтАЩsdistance is given by the relation,
Where,
╬╗ =Wavelength of radio waves
Therefore, the wavelength of theradio waves is 12.5 cm.