Jawaharlal Nehru Technological University Kakinada 2008 B.Tech Electronics and Communications Engineering electronic circuit analysis - Question Paper

6. (a) Compare and discuss the frequency response of single tuned, double tuned
and staggered tuned ampli?ers.
(b) A single tuned RF ampli?er uses a transistor with an output resistance of 60K,
output capacitance of 20PF and input resistance of next stage in 20kO. The
tuned circuit consists of 47PF capacitance is parallel with series combination
of 1µH inductance and four O resistance. Calculate:
i. Resonant frequency
ii. E?ective quality factor
iii. Bandwidth of the circuit. [8+8]
7. (a) Draw a neat circuit diagram of a series regulator and discuss its working.
(b) For the emitter follower series voltage regulator shown in ?gure 1, compute
the output voltage and the zener current if RL=1k O. [8+8]
Figure 1:
8. (a) Explin how three terminal IC 7805 in used as a current source with a neat circuit
diagram.
(b) Draw the circuit of volatage multiplier and discuss its principle. elaborate its
applications. [8+8]
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2 of 2Code No: 07A3EC14 Set No.3
II B.Tech. I Semester Regular Examinations, November -2008
ELECTRONIC CIRCUIT ANALYSIS
( Common to Electronics & Communication Engineering and Electronics &
Telematics)
Time: three hours Max Marks: 80
ans any 5 ques.
All ques. carry equal marks
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1. (a) Draw hybrid-p equivalent of a transistor in CE con?guration at low frequency.
explain the signi?cance of di?erent parameters of the equivalent circuit.
(b) The h-parameter a.c equivalent circuit of a transistor in CE mode is shown in
?gure 2. compute AI , AV = VL
VS
, Zin and Zout. [8+8]
Figure 2:
2. (a) Compare emitter follower and darlington emitter follower con?gurations in
respect of
i. current gain
ii. input impedance
iii. voltage gain
iv. output impedance.
(b) For the circuit shown in ?gure 3, compute Ri, Ai, Av and Ro. presume
hie=1.1K, hfe=50, hre=2.5×10-4, hoe=25 µA/v. [8+8]
3. (a) Derive the expression of gain bandwidth product for current.
(b) A HF ampli?er uses a transistor which in driven from a source with Rs=0.
compute value of fH, if RL=0 and RL=1KO. Typical values are rb0
e = 1K,
Ce=100PF and, Cc=3PF and gm=50 mA/V. [8+8]

Earning:   Approval pending.