Question
Download Solution PDFIn an amplifier with input impedance Zi and output impedance Zo, when a current series feedback is introduced
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFThe four basic feedback topologies are as shown:
i) Voltage-Series feedback with voltage amplifier:
Input Resistance:
\({R_{if}} = {R_i}\left( {1 + A\beta } \right)\) (Increases)
Output Resistance:
\({R_{of}} = \frac{{{R_o}}}{{1 + A\beta }}\) (Decreases)
ii) Current-Series feedback with a transconductance amplifier:
Input Resistance:
\({R_{if}} = {R_i}\left( {1 + A\beta } \right)\) (Increases)
Output Resistance:
\({R_{0f}} = {R_0}\left( {1 + A\beta } \right)\) (Increases)
iii) Current-Shunt feedback with a current amplifier:
Input Resistance:
\({R_{if}} = \frac{{{R_i}}}{{1 + A\beta }}\) (Decreases)
Output Resistance:
\({R_{of}} = {R_o}\left( {1 + A\beta } \right)\) (Increases)
iv) Voltage-Shunt feedback with trans resistance amplifier:
Input Resistance:
\({R_{if}} = \frac{{{R_i}}}{{1 + A\beta }}\) (Decreases)
Output Resistance:
\({R_{of}} = \frac{{{R_o}}}{{1 + A\beta }}\) (Decreases)
Last updated on May 30, 2025
-> The ISRO Technical Assistant recruitment 2025 notification has been released at the official website.
-> Candidates can apply for ISRO recruitment 2025 for Technical Assistant from June 4 to 18.
-> A total of 83 vacancies have been announced for the post of Technical Assistant.
-> The Selection process consists of a written test and a Skill test.
-> Candidates can also practice through ISRO Technical Assistant Electrical Test Series, ISRO Technical Assistant Electronics Test Series, and ISRO Technical Assistant Mechanical Test Series to improve their preparation and increase the chance of selection.