two towers on top of hills are 40 km apart . the line joining them passes 50 m above a hill halfway
between the tower .what is the largest wavelength of radio waves ,what is the larges wavelength of radio waves ,which can be sent between the towers without appreciable diffraction effects

Asked by vinodjoshi112233 | 7th Dec, 2017, 08:40: PM

Expert Answer:

Answer to the problem is to find out the path difference between the direct transmission path ( PSQ) and the reflected transmission path(PRQ).
 
The path difference can be calculated as 125 cm.
To avoid diffraction effect it is required to have constructive interference between the direct radio wave and the reflected radio wave at Q.
For this, the path difference should be nλ, where n is integers and λ is wavelength of raido wave transmitted.
 
Hence λ of radio wave should be integer multiple of 125 cm

Answered by  | 8th Dec, 2017, 12:33: PM