ECA SECOND MID BITS

Note: Don't think that these bits only will be repeated in Second mid .First go through the concepts thoroughly then solve the bits.

ECA

JNTUH BITS

UNIT-5: Feedback amplifiers

SECTION-I: Multiple choice questions

1. Negative feedback in amplifier [ b ]

(a) Improves SNR at the input (b) improves SNR at the output (c) Increases distortion (d) None of the above

2. The gain of an amplifier with feedback is ______. [ a ]

(a) A/1+Aβ (b) β/1+βa (c) β/1-βa (d) A/1-Aβ

3. In voltage shunt feedback, the input impedance [ b ]

a. increases b. decreases

c. depends on dc voltage applied d. depends on frequency of operation

4. Which of the following combination can be used as a buffer_____ [ c ]

a. CE b. CB c. CC d. All

Section-II: Fill in the blanks

1. The Trans conductance amplifier is also called as Series – Series amplifier (or) Current – Series amplifier

2. In an ideal voltage amplifier, the values of Ri & R0 are ∞, 0

3. The ratio of input impedance with feedback to without feedback is 1+Aβ