question_answer 18)

TWO towers on top of two hills are 40 kmapart. The line joining them passes50 m above a hill halfway between the towers. What is the longest wavelength of radiowaves, which can be sent between the towerswithout appreciable diffraction effects ?  

Answer:

If A and B are two hills and C is the hillpeak mid way. Then, using the diffractioncondition, orFor longest wavelength n = 1 and or