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The antenna current of an AM transmitter...

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 by a single sine wave. Find the percentage modulation

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The modulated or total power carried by AM wave `P_(T)= P_(C)( 1+ (m^(2))/(2))` If R is load resistance , `I_(m)` is the current when carrier is modulated and `I_(c)` the current when unmodulated then,
`(P_(T))/(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)= 8.93 A, I_(c)= 8A`
`:. m^(2)= 2[((8.93)/(8.0))^(2)-1]:. m= 0.7`
Therefore, percentage modulation=70%
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