B.E. (Third semester) EXAMINATION, Dec. 2008
(Common for EC/EE/EX Engg.)
Note: Attempt any five questions. All question carry equal marks. Assume any missing data.
1. (a) For a CE circuits shown in Fig. 1, calculate the values of IB, IC IE and VCE. . Assume B=50 and neglect
(b) Describe a Zener diode . Distinguish Between Zener breakdown and avalanche breakdown.
2. (a) How will you draw d.c. load line on the output characteristics of a transistor ? What is the
importance ? Define operating point.
(b) A JEFT has a drain current of 5mA . if IDSS is 10 mA and VGS OFF IS -6V, find the value of VGS and VP.
3. (a) Explain the classification of amplifiers .
(b) Explain briefly class A and B amplifiers .
4. (a) What is Oscillator and RC phase shift oscillator ? Explain RC phase shift oscillator in detail.
(b) Draw and explain the circuit of a Wien bridge oscillator .
(c ) A single transistor is operating as an ideal Class B amplifier with a k load . The collector current is
10mA . How much signal power is delivered to the load ?
5. (a) What do you mean by reserve recovery time of a transistor ? How the transistor is used as a
(b) Calculate d.c. bias values of IC and VC and for the matched transistor of ahead fig. 2. Assume
6. (a) Draw a Darlington emitter follower . Explain Why the input impedance is higher than that of a
single stage emitter follower.
(b) Write a short note on multavibrator.
7. (a) Define the following terms:
(i) Slew rate
(ii) Full power bandwidth
(iii) Offset voltage
(b) Explain the low pass and high pass filters using OP-AMP . Draw their frequency response
8. (a) Draw and explain the following OP-AMP applications as:
(i) Instrumentation amplifier
(ii) Voltage to current converter.
(b) What is the main difference between square wave generator and Schmitt trigger ? Explain Schmitt
Trigger in detail.
9. (a) Write the principle of voltage regulator . What do you understand by SPMC ?
(b) Explain series and shunt regulators.
10. Write short notes on any two of the following :
(ii) 555 timer
(iv) Boot strapping