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Question 11.3: (a) A multistage amplifier employs five stages each of which...

(a) A multistage amplifier employs five stages each of which has a power gain of 30. What is the total gain of the amplifier in dB? (b) If a negative feedback of 20 dB is employed, find the resultant gain.

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Given, the gain of each stage = 30 and number of stages = 5

(a) Power gain of one stage = 10 \log_{10} 30 = 10 × 1.477 = 14.77 dB

Total power gain = 5 × 14.77 = 73.85 dB

(b) The resultant power gain with negative feedback = 73.85 – 20 = 63.85 dB

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