Two identical antennas mounted on identical towers are separated from each other by a distance of 45 km. What should nearly be the minimum height of receiving antenna to receive the signals in line of sight? (Assume radius of earth is 6400 km)
Show Hint
- \(158.2\ \mathrm{m}\)
- \(79.1\ \mathrm{m}\)
- \(19.77\ \mathrm{m}\)
- \(39.55\ \mathrm{m}\)
The Correct Option is D
Solution and Explanation
Range of one antenna: \(d = \sqrt{2Rh}\), so \(h = \frac{d^2}{2R} = \frac{(2.25\times 10^4)^2}{2\times 6.4\times 10^6} = \frac{5.0625\times 10^8}{1.28\times 10^7} = 39.55\ \mathrm{m}\).
Answer: (4) \(39.55\ \mathrm{m}\)
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