A TV transmitting antenna is 128 ~m , tall. If the receiving antenna is at the ground level, the maximum distance between, them for satisfactory communication in line of sight mode is (radius of the earth 6.4 10^6 ~m )

Step-by-step solution

Height of transmitting antenna d 2 R_e h_T Given aligned R_e & =6.4 10^6 ~m h_T & =128 ~m d & =? aligned The maximum distance aligned & d= 2 6.4 10^6 128 & d= 128 10^5 128 & d= 128 10^2 10 10 10 & d= 128 10^3 10 ~m = 128 10 ~km aligned