Modern Physics Ques 272
- A TV transmission tower has a height of $140$ $ m$ and the height of the receiving antenna is $40$ $ m$. What is the maximum distance upto which signals can be broadcasted from this tower in LOS (Line of Sight) mode? (Take, radius of earth $=6.4 \times 10^{6} $ $m$ ).
(Main 2019, 10 Jan I)
(a) $65 $ $km$
(b) $80 $ $km$
(c) $40 $ $km$
(d) $48 $ $km$
Show Answer
Answer:
Correct Answer: 272.(a)
Solution:
- Maximum distance of transmission is given by
$ d=\sqrt{2 R h _T}+\sqrt{2 R h _R} $
where, $\quad h _T=$ height of transmitter, $=140$ $ m$,
$ h _R=\text { height of receiver }=40$ $ m \text { and } $
$ R=\text { radius of earth }=6.4 \times 10^{6}$ $ m $
Substituting values, we get
$ d=\sqrt{2 \times 6.4 \times 10^{6}}(\sqrt{140}+\sqrt{40})=65 $ $km $
BETA
