West Bengal Institute of Technology (WBIT) 2011-4th Sem B.Tech Electronics and Communications Engineering B-TECH ANALOG ELECTRONIC CIRCUITS,,ESTER,WBUT - Question Paper

a) W=1.1 RC
b) W=0.693 RC
c) W=1/0.693 RC
d) W=1.1/RC.
xv) For ideal regulated power supply line regulation should be
a) maximum
b) 50%
c) zero
d) 70%.

GROUP-B
(Short ans kind questions)
ans any 3 of the subsequent. 3*5=15

2. Draw the Ebers-Moll model of the n-p-n transistor & provide the formula for the emitter & collector current. 5
3. obtain out the Q point for a fixed bias circuit having a silicon transistor with ß =100, supply voltage Vcc =6V, Collector resistor Rc = three kohm,and base resistor Rb = 530 kohm. 5
4. describe and classify filters. find the transfer function of 1st order HPF using Op-amp as active element. 2+3
5. Draw the circuit diagram if an Astable Multivibrator with 50% duty cycle output using 555 timer. 5
5. elaborate the limitations of an ordinary Op-Amp differentiator? Draw the circuit of a practical differentiator that will eliminate these limitations. 2+3


GROUP-C
(Long ans kind Questions)
ans any 3 of the subsequent. 3*15=45

7. a) elaborate the factors affecting stability of Q point?
b) Draw and discuss voltage divider biasing circuit. Also compute the stability factor of this biasing circuit?
c) What is thermal runaway in the transistor amplifier circuit?
3+10+2

8. Draw the circuit diagram of a push-pull class B power amplifier and discuss its working.
compute the power conversion efficiency of it and maximum collector power
dissipation. 1+6+5+3

9. a) Draw the circuit diagram of a class C power amplifier and discuss.
b) find the expression for efficiency of a class B amplifier and mention its maximum
value.
c) discuss the operation of a push-pull amplifier with suitable circuit diagram.
5+4+6
10. What is regulated power supply? elaborate the factors affecting output voltage of a
regulated power supply ? State the performance parameters of regulated power
supply. discuss the shunt and series regulated power supply with block diagram.
1+3+3+4+4

11. a) Draw the circuit of Wien-bridge oscillator using Op-Amp and define its working.
obtain an expression for the frequency of oscillation.
b) A wien- bridge oscillator is to span a range of frequencies from 30 Hz to 30 kHz . The
variable capacitance can be changed from 50 pf to 500 pf. obtain the resistances needed to
span the frequency range. If the gain of the amplifier is 6, what must be the ratio of the
resistances in the other arms if bridge? (4+6)+5

12. Write short notes on any 3 of the following: 3*5=15
a) Clamping and clipping circuit.
b) Tuned amplifier
c) Antilog amplifier
d) Precision rectifier
e) Triangular wave generator.

Earning:   Approval pending.