InterviewSolution
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InterviewSolution
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A ground receiving station is receiving a signal at 6MHz transmitted from a ground transmitter at a height of 500m located at a distance of 100km. If radius of earth is `6.4xx10^(6)`m, maxim um number density of electron in ionosphere is `10^(12)m^(-3)`. the signal is coming via:A. ground waveB. spac e waveC. Sky wave propagation is useful in the range of 30 to 40 MHz.D. satellite transponder |
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Answer» Correct Answer - C Maximum distance covered b y space wave communication is `d=sqrt(2Rh)=sqrt(2xx(6.4xx10^(6))xx300)=80xx10^(3)m=80km` Since the distance between transm itter and receiver is 100km, hence for the given frequency signal of 6 MHz. the propagation is not possible via space propagation. for sky wave propagation the critical frequency. `v_(c)=9(N_("max"))^(1//2)=9xx(10^(12))^(1//2)=9xx10^(6)Hz=9MHz` Since 6 MHz `lt9 MHz`. so the propagation of signal of frequency 6 MHz is possible via sky wave. |
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