Question -
Answer -
Distance between the towers, d = 40 km
Height ofthe line joining the hills, d =50 m.
Thus, theradial spread of the radio waves should not exceed 50 km.
Since thehill is located halfway between the towers, Fresnel’s distance can be obtainedas:
ZP =20 km = 2 × 104 m
Aperturecan be taken as:
a = d = 50 m
Fresnel’sdistance is given by the relation,
Where,
λ =Wavelength of radio waves
Therefore, the wavelength of theradio waves is 12.5 cm.