Question

21. Calculate the internal voltage gain, the total voltage gain, input and output resistances of the network amplifier shown below when 2k92, 91 - 50092, A1 = 10, R2 3k92, r2 = 80092, A2 = 5, R3 = 4k12, 13 = 50092, A3 = 7, Rs = 2.7k 2, and Ru = 8kQ? Ri Rs W ina Ri 71 A V R2 72 Az v2 R Sus Asus RI to Ru rou Ria ko2 Tog Ω Avo Avt =

Answer 1

Rs 83 MW 's +7 Ri t RzV2 AV2 Ay 3 'Rior 81=500 2 Row Rs = 2.7k2 R = 2k2 A₂=5 82=800.2 Aia to R2 =Bk2 A3=7 83²5002 R₂ = 8ksh R₂ = 46.2 input resistance is given by + Tim Ri Van qR, Iin -Xeo Rig =R. = 2ks Vs=0 Ourput resistance Shoot circuired Voc - AzV3 Bxc = meas used when Input supply then V = V2 = V3 zov 83 wirk + Voc 03 TA & ROON Row Ix Roq=&= 500 R from diagram can find R2 Vz AVI AVR2 & +R2 8 + R2 vas R3 22+R3 AU2 AzR3 &+R3

R3 A2 V2 AzV3 A3 - Here Az is replaced by Avoy whichich Ano is AR2 - ARAZ R3 R₂ +82 R2 +8 .. internal gain R3 R2 A voli = A₂A₂A, Vi R3+02 R₂th so w T Avo R382 Rata R Vs 3000 Loco 7 XSXIOX 3000 t Soo 4000+800 4000 950 x = 35 ox0.83331 0.9572 3000 3500 X 4800 Avo 250 RIARS vur Output Voirne is given by RL RLTOR Vous us RARS Ret gooo Vou - 2.50 Scoot 500 2000+2700 Vs You = 250 X 0,941 X 0.425, 100.125 Viv Avr Ava 2 100 125 Avo = 250 = 2k2 Roq = 5002