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The antenna current of an AM transmitter is 8A when only the carrier is sent but it increases to 8.93A when the carrier is modulated. Find percent modulation. |
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Answer» SOLUTION :The modulated or total power carried by AM wave `P_(tau)=P_(C)(1+(m^(2))/(2))` Id R is load RESISTANCE, `I_(m)` is the current when carrier is modulated and `I_(c)` the current when un-modulated, then `(P_(tau))/(P_(C))=(I_(m)""^(2)R)/(I_(c)""^(2)R)"":.I+(m^(2))/(2)=(I_(m)""^(2)R)/(I_(c)""^(2)R)` Given `I_(m)=8.93A,I_(c)=8A` `:.m^(2)=2[((8.93)/(8.0))^(2)-1]:.m=0.7` Therefore, percentage modulation `=70%` |
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