Pondicherry University 2007 Bio-Medical Enggineering (B.Tech) - exam paper

B.Tech DEGREE EXAMINATION,NOV 2007

3rd SEMESTER

EIE/BIO MEDICAL ENGINEERING

ELECTRONIC CIRCUITS – 1

Time : 3 hours Maximum :75 marks

ans all ques..

Unit – 1

1. (a) Draw the volt –ampere characteristics of PN junction diode and discuss about reverse saturation current. (8)

(b) With the help of relevant diagrams ,explain how the diode is used as rectifier. (7)


(or)

2. (a) define the physical mechanism for Zener breakdown. (8)

(b) discuss how to find maximum power output from a photovoltaic cell. (7)

Unit – 2

three . (a) sketch a family of CB output characteristics for a transistor and discuss the different operating regions. (8)

(b) Derive the expression for Ic versus Ib for a CE transistor
Configuration in the active region (7)


(or)
4. (a) derive the relationship ranging from Hfe and hfe. (8)

(b) discuss the 3 consequences of base width modulation (7)


UNIT – 3

5. (a) Draw the basic structure of n-channel junction field effect transistor and discuss its construction. (8)

(b) describe the pinch –off voltage Vp and sketch the depletion region and after pinch – off. (7)

(or)


6. (a) Draw 2 biasing circuits for an enhancement –type MOSFET and discuss. (8)

(b) Draw and discuss the characteristics of SCR with circuit symbol. (7)


UNIT – 4

7. (a) For a capacitively coupled load,is the dc load larger or smaller than the ac load ? discuss. (8)


(b) Derive the expressions for current gain and input impedance for the basic amplifier circuit model. (7)


(or)

8. (a) Derive the expressions for current gain and input impedance for the basic amplifier circuit model. (8)
(b) Draw the circuit of a CE transistor configuration and provide its h-parameter model. (7)


UNIT – 5

9. (a) Draw a darlington emitter follower and discuss why the input impedance is higher than that of a single – stage emitter follower. (8)


(b) State and discuss miller’s theorem with the aid of a circuit diagram. (7)



(or)


10. Draw the source-follower configuration of FET amplifier and its equivalent circuit at small –signal high-frequency and derive the expressions for voltage gain, input admittance and output admittance. (15)

Earning:   Approval pending.