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(B) $1$. Calculate the maximum line-of-sight distance for space wave communication: $d_m = \sqrt{2Rh} = \sqrt{2 	imes 6.4 	imes 10^6 	imes 300} = \

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Sky wave propagation

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(B) $1$. Calculate the maximum line-of-sight distance for space wave communication: $d_m = \sqrt{2Rh} = \sqrt{2 	imes 6.4 	imes 10^6 	imes 300} = \sqrt{3840 	imes 10^6} \approx 61.97\, km \approx 62\, km$.$2$. Since the distance between the transmitter and receiver is $100\, km$,which is greater than $d_m$ $(100\, km > 62\, km)$,space wave propagation is not possible.$3$. Calculate the critical frequency of the ionosphere: $f_c = 9(N_{\max})^{1/2} = 9 	imes (10^{12})^{1/2} = 9 	imes 10^6\, Hz = 9\, MHz$.$4$. Since the signal frequency $(5\, MHz)$ is less than the critical frequency $(9\, MHz)$,the signal can be reflected by the ionosphere.$5$. Therefore,the signal is received via sky wave propagation.

Column $A$	Column $B$
$A$. $D$-layer	$I$. $250-400 \ km$
$B$. $E$-layer	$II$. $170-190 \ km$
$C$. $F_1$-layer	$III$. $95-120 \ km$
$D$. $F_2$-layer	$IV$. $65-75 \ km$

$A$. Optical Fiber Communication	$P$. Ultrasound
$B$. Radar	$Q$. Infrared Light
$C$. Sonar	$R$. Microwaves
$D$. Mobile Phones	$S$. Radio Waves

Similar Questions

Match Column $A$ (layers in the ionosphere for skywave propagation) with Column $B$ (their height range).
Column $A$ Column $B$
$A$. $D$-layer $I$. $250-400 \ km$
$B$. $E$-layer $II$. $170-190 \ km$
$C$. $F_1$-layer $III$. $95-120 \ km$
$D$. $F_2$-layer $IV$. $65-75 \ km$

The modulation index for an $A.M.$ wave having maximum and minimum peak-to-peak voltages of $14\,mV$ and $6\,mV$ respectively is:

The amplitude of $15 \sin (1000 \pi t)$ is modulated by $10 \sin (4 \pi t)$ signal. The amplitude modulated signal contains frequency(ies) of
$A) 500 \text{ Hz}$
$B) 2 \text{ Hz}$
$C) 250 \text{ Hz}$
$D) 498 \text{ Hz}$
$E) 502 \text{ Hz}$
Choose the correct answer from the options given below:

$A$ modulated signal $C_m(t)$ has the form $C_m(t) = 30 \sin(300\pi t) + 10 \cos(200\pi t) - 10 \cos(400\pi t)$. The carrier frequency $f_c$,the modulating frequency $f_m$,and the modulation index $\mu$ are respectively given by:

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