Why is the communication using line of sight mode limited to frequencies above 40 MHz?

(i) Why is communication using line of sight mode limited to frequencies above 40 MHz? (ii) A transmitting antenna at the top of a tower has a height 32 m and the height of the receiving antenna is 50m . What is maximum distance between them for satisfactory communication in line of sight mode ?

(i) Why is communication using line of sight mode limited to frequencies above 40 MHz? (ii) A transmitting antenna at the top of a tower has a height 32 m and the height of the receiving antenna is 50m . What is maximum distance between them for satisfactory communication in line of sight mode ?

A transmitting antenna of height h and the receiving antenna of height 45 m are separated by a distance of 40 km of satisfactory communication in line of sight mode. Then the value of h is (given radius of earth is 6400 km)

A transmitting antenna of height 20 m and the receiving antenna of height h are separated by a distance of 40 km for satisfactory communication in line of sight (Los) mode. Then the value of his (Give, radius of earth is 6400 km.

Distinguish between 'sky wave' and ' space wave' modes of propagation. Why is the sky wave mode of propagation restricted to frequencies upto 40 MHz ?

A transmitting antenna of height 20 m and the receiving antenna of height h are separated by a distance of 40km for satisfactory communication in line of sight mode. Then the value of h is

A transmitting antenna of height 20 m and the receiving antenna of height h are separated by a distance of 40km for satisfactory communication in line of sight mode. Then the value of h is

A transmitting antenna of height 20 m and the receiving antenna of height h are separated by a distance of 40km for satisfactory communication in line of sight mode. Then the value of h is

A transmitting antenna of height 20 m and the receiving antenna of height h are separated by a distance of 40km for satisfactory communication in line of sight mode. Then the value of h is