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Grade 12Modern Physics

An npn transistor operates as a common emitter amplifier with a power gain of 60dB .The input circuit resistance is 100 ohm and the output load resistance is 10000 ohm. The common emitter current gain is?

Profile image of Jay Saini
7 Years agoGrade 12
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1 Answer

Profile image of Mayank
7 Years ago
we know that  power gain = voltage gain * current gain  so now current gain =\beta  and voltage gain = (\beta* R)/r where R =output load resistance and r=input load resistance so now the power gain =(\beta*\beta*R)/r so  now numerically we have 
 
   60=(\beta*\beta*10000)/100 so from here we get  \beta*\beta=0.6  and hence \beta=0.77459