JEE Main · 2021 · 27 Aug 2021 · Shift 1 · EM Waves

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A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is 'd'. The value of 'd' is ______ km.

Answer: 224

Solution

For line-of-sight communication, the maximum distance is

d = 2 R h_{T} + 2 R h_{R}

where

R = 6400

km is Earth's radius,

h_{T} = 0.32

km and

h_{R} = 2

km are antenna heights.

d = 2 \times 6400 \times 0.32 + 2 \times 6400 \times 2

d = 4096 + 25600 = 64 + 160 = 224 km

JEE Main · 2021 · 27 Aug 2021 · Shift 1 · Integer answer

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