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JEE Main202116 Mar 2021Evening ShiftPhysicsCommunication SystemActual

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 )

Options

  1. A19 . 77   m
  2. B39 . 55   m
  3. C79 . 1   m
  4. D158 . 2   m

Correct answer

B. 39 . 55   m

Step-by-step solution

D = 2 2 R h h = D 2 8 R = 45 2 8 × 6400   km ≅ 39 . 55   m

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