ECA
JNTUH second Mid 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