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In a FM system, the maximum deviation is 75KHz. Find bandwidth for modulating frequency i. fm=500Hz ii. fm=5KHz iii. fm=10KHz Draw conclusion for bandwidth of FM from answer.

1 Answer

Given deviation∆=75kHz

i) fm=500Hz

bandwidth B.W=2(∆+fm)

 =2(75k+500)=151kHz

 ii). fm=5KHz

bandwidth B.W=2(∆+fm)

 =2(75k+5k)=160KHz

iii) fm=10KHz

bandwidth B.W=2(∆+fm)

 =2(75k+10k)=170KHz

As the modulating frequency increases bandwidth also increases.
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