Feedback Amplifiers

Question 1
A good transimpedance amplifier has
A
low input impedance and high output impedance.
B
high input impedance and high output impedance.
C
high input impedance and low output impedance.
D
low input impedance and low output impedance.
GATE EC 2018   Analog Circuits
Question 1 Explanation: 
A good transimpedance amplifier should have low input impedance and low output impedance
Question 2
A good transconductance amplifier should have
A
high input resistance and low output resistance
B
low input resistance and high output resistance
C
high input and output resistances
D
low input and output resistance
GATE EC 2017-SET-1   Analog Circuits
Question 2 Explanation: 
A good transconductance amplifier should have very high input resistance and very high output resistance.
Question 3
The desirable characteristics of a transconductance amplifier are
A
high input resistance and high output resistance
B
high input resistance and low output resistance
C
low input resistance and high output resistance
D
low input resistance and low output resistance
GATE EC 2014-SET-3   Analog Circuits
Question 4
The feedback topology in the amplifier circuit ( the base bias circuit is not shown for simplicity) in the figure is
A
Voltage shunt feedback
B
Current series feedback
C
Current shunt feedback
D
Voltage series feedback
GATE EC 2014-SET-2   Analog Circuits
Question 4 Explanation: 
The feedback topology in the amplifier circuit is
current series because
Sampling \rightarrow Current
Mixing \rightarrow Series
So current-series feedback
Question 5
In the ac equivalent circuit shown in the figure, if i_{in} is the input current and R_{F} is very larger, the type of feedback is
A
voltage-voltage feedback
B
voltage-current feedback
C
current-voltage feedback
D
current-current feedback
GATE EC 2014-SET-1   Analog Circuits
Question 5 Explanation: 
Sampling \rightarrow current
Mixing \rightarrow voltage
Question 6
In a voltage-voltage feedback as shown below, which one of the following statements is TRUE if the gain k is increased?
A
The input impedance increases and output impedance decreases.
B
The input impedance increases and output impedance also increases.
C
The input impedance decreases and output impedance also decreases.
D
The input impedance decreases and output impedance increases.
GATE EC 2013   Analog Circuits
Question 6 Explanation: 
The given configuration is a voltage-series feedback configuration.
So, the input impedance increases
R_{i f}=R_{i}\left(1+A_{0} K\right)
and, the output impedance decreases
R_{o f}=\frac{R_{o}}{1+A_{o} K}
Question 7
In a transconductance amplifier, it is desirable to have
A
a lage input resistance and a large output resistance
B
a large input resistance and a small output resistance
C
a small input resistance and a large output resistance
D
a small input resistance and a small output resistance
GATE EC 2007   Analog Circuits
Question 8
The input impedance (Z_{i}) and the output impedance (Z_{0}) of an ideal transconductance (voltage controlled current source) amplifier are
A
Z_{i}=0,Z_{0}=0
B
Z_{i}=0,Z_{0}=\infty
C
Z_{i}=\infty ,Z_{0}=0
D
Z_{i}=\infty ,Z_{0}=\infty
GATE EC 2006   Analog Circuits
Question 9
The effect of current shunt feedback in an amplifier is to
A
increase the input resistance and decrease the output resistance
B
increases both input and output resistance
C
decrease both input and output resistance
D
decrease the input resistance and increase the output resistance
GATE EC 2005   Analog Circuits
Question 10
Voltage series feedback (also called series-shunt feedback) results in
A
increase in both input and output impedances
B
decrease in both input and output impedances
C
increase in input impedance and decrease in output impedance
D
decrease in input impedance and increase in output impedance
GATE EC 2004   Analog Circuits
There are 10 questions to complete.
Like this FREE website? Please share it among all your friends and join the campaign of FREE Education to ALL.