ANALOG ELECTRONICS
ASSIGNMENT-1
1.
E
xplain and analyse with the help of circuit diagram, a current-shunt feedback amplifier.
2.
A
negative feedback of β=0.002 is applied to our amplifier of gain 1000. Calculate the change in
overall gain of the feedback amplifier if the internal amplifier is subjected to a gain reduction of
15%.
3.
D
raw the block diagram of a negative feedback amplifier. Derive an expression for the voltage
gain of an amplifier of gain A when subjected to negative feedback with a feedback fraction B.
4.
S
how that the negative feedback in amplifiers increases the bandwidth and improves signal to
noise ratio.
5.
D
raw and explain the current shunt feedback.
6.
W
hat are the four possible topologies of a feedback amplifier? Identify the output signal X o and
feedback signal Xf for each topologies (either as current or voltage).
7.
E
xplain and analyse with the help of circuit diagram, a current-series feedback amplifier.
8.
I
f the open loop gain Av =10,000 and feedback factor β=1/10 then for a negative feedback, find
the percentage change in closed loop gain varies 50% with temperature. With the help of this
example show that the stability increased with negative feedback.
9.
G
ive complete classification of feedback amplifiers with the help of neat diagram.
10.
D
raw the block diagram of a negative feedback amplifier. Derive an expression for the voltage
gain of an amplifier of gain A when subjected to negative feedback with a feedback fraction B.
11.
D
iscuss with the help of a circuit example, the purpose of providing
(i) negative feedback (ii) positive feedback in amplifier
12.
W
hat are the four possible topologies of a feedback amplifier? Identify the output signal X o and
feedback signal Xf for each topologies (either as current or voltage).
13.
L
ist the steps required to carry out the analysis of a feedback amplifier. Explain in brief.
ASSIGNMENT-2
1.
E
xplain in brief with help of circuit diagram, with bridge oscillator. Also determine the equation
for oscillating frequency?
2.
F
ind the C & hfe of a transistor to provide resonating frequency to of 10 KΩ of a RC phase shift
oscillator. Given R1 = 22 KΩ, R2 = 68 kΩ, Rc = 20 kΩ, R = 6.8KΩ.
3.
S
tate the barkhausen conditions for an electronic system to oscillate with feedback.
4.
D
raw the circuit diagram of a colpitts oscillator and explain its working.
5.
D
raw the circuit diagram of an RC phase shift oscillator and obtain an expression for its frequency
of oscillation.
6.
D
ifferentiate between the Monostable and Bistable multivibrator.
7.
W
rite short note on crystal oscillator?
8.
E
xplain working of Transistor Colpitt oscillator with neat circuit diagram?
9.
S
ketch the circuit for a wein bridge oscillator. What determines the frequency of oscillation? Will
oscillations take place if the bridge is balanced?
10.
D
raw and explain the operation of Schmitt trigger circuit. Also draw its transfer characteristics?
ASSIGNMENT-3
1.
etermine gain bandwidth product, unity gain frequency using hybrid
configuration.
2.
D
model for CE
A
CE-connected amplifier has Ccb= 5pF, Cbe= 12pF, hfe=100 and hie=1.5kΩ. Determine input
capacitance to the circuit for a circuit collector resistance of 12Ω.
3.
D
erive the expression for the CE Short Circuit Current gain Ai as a function of frequency?
4.
D
raw the circuit diagram of emitter follower at high frequencies. Also explain its behavior at high
frequencies with necessary expression and parameter?
5.
A
transistor with alpha cut-off frequency =5MHz and hfe or =50 is used in a CE configuration.
When connected to an amplifier, it has stray capacitance of 80pF at the output terminals.
Determine the upper 3dB frequency when (i) RL= 10kΩ and (ii) RL=100kΩ.
6.
E
xplain how you would arrive at the hybrid π equivalent circuit model in CE configuration at high
frequencies. Explain the different parameters involved in the circuit.
7.
F
ollowing transistor measurements made at IC = 5mA, VCE = 10V and at room temperature. hfe =
100, hie = 600Ω |Ai| = 10 at 10 MHz and CC = 3 pF. Find fβ, fT, Ce, rb`e, rbb`.
ASSIGNMENT 4
1.
2.
3.
4.
5.
6.
7.
8.
9.
W
hat is a parallel resonance? What are its features? How is it different from series resonances?
Ex
plain the reasons for potential instability in tuned amplifiers.
Draw the circuit diagram of a collector tuned
amplifier and derive expressions for the voltage gain at the tuned frequency and bandwidth.
Ex
plain in brief the advantage of using double tuned circuit over a single tuned circuit. Draw the
circuit diagram of double tuned amplifier and its frequency response.
Dra
w circuit of single tuned amplifier and explain its working with frequency response curve.
Dra
w parallel resonant circuit and obtain the expression for its bandwidth.
Ex
plain the frequency response of stagger tuned amplifier?
Dra
w and explain the circuit of double tuned amplifier with the help of frequency response?
Th
e single tuned amplifier with capacitive coupling consists of tuned circuit having R = 10Ω, L
= 20 mH, C = 0.05µF. Determine
a) Resonant frequency
b) Q-factor
c) Band width of amplifier.
ASSIGNMENT 5
1.
W
hat do you understand by class A, B and C power amplifiers?
2.
S
how that maximum collector efficiency of class A transformer coupled power amplifier is 50%.
3.
D
raw the circuit diagram of a push pull amplifier. Explain its operation. Discuss its advantages
and disadvantages.
4.
D
etermine the overall efficiency of class b power amplifier when VCC = 20V and VCEmin = 2.5V?
5.
D
raw the circuit of class D and Class E amplifier and their application.