Download Aptitude Crack
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Communication Systems - Engineering

Q1:

In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then

A amplitude of distant sidebands decreases

B amplitude of distant sidebands increases

C amplitude of distant sidebands remains constant

D amplitude of distant sidebands first increases, then decreases

ANS:B - amplitude of distant sidebands increases

I think distant side bands decrease. Because at the constant modulating voltage and lower modulating frequency, the modulation index is very large. And it comes in the category of wideband frequency modulation. In which frequency domain representation of wide band gives us that side bands are decreased.