### Operational Amplifier Fundamentals And Effect Of Feedback In Amplifier Multiple Choice Questions And Answers

Operational Amplifier Fundamentals And Effect Of Feedback In Amplifier Multiple Choice Questions And Answers 1. Negative feedback in an amplifier a) Reduces gain b) Increase frequency &phase distortion c) Reduces bandwidth d) Increases noise Answer: Reduces gain 2. A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by a) 2 b) 1 c) 1/2 d) 0 Answer: 2 3. The approximate input impedance of the OPAMP circuit which has Ri=10k, Rf=100k, RL=10k a) ∞ b)120k c)110k d)10k Answer: 10k 4. An amplifier using an opamp with slew rate SR=1v/Î¼sec has a gain of 40db.if this amplifier has to faithfully amplify sinusoidal signals from dc to 20 KHz without introducing any slew-rate induced distortion, then the input signal level must not exceed a) 795mV b) 395mV c) 795 mV d) 39.5mV Answer: 795 mV 5. An ideal OP-AMP is an ideal a) Current controlled Current source b) Current controlled voltage source c) Voltage controlled voltage source d