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Anna University** **EC
294 / EC9213 – ELECTRONIC DEVICES AND CIRCUITS April May 2014, Computer Science and Engineering, Third Semester, Regulations 2004/2008

Exam |
B.E/B.Tech. (Full
Time) DEGREE END SEMESTER EXAMINATIONS |

Academic
Year |
April May 2014 |

Subject
Code |
EC 294 / EC 9213 |

Subject
Name |
Electronic Devices and Circuits |

Branch |
Computer Science and Engineering |

Semester |
Third semester |

Regulation |
2004 and 2008 |

**B.E / B.Tech. (Full Time) DEGREE END SEMESTER EXAMINATIONS, APRIL / MAY 2014**

Computer Science
and Engineering

Third Semester

**EC 294 / EC9213 – ELECTRONIC DEVICES AND CIRCUITS**

(Regulations 2004/2008)

Time : 3 Hours Answer A L L Questions Max. Marks 100

**PART-A (10 x 2 = 20 Marks)**

1. Find voltage across resistor R

_{L}in figure 1.
2. Find the curren through resistorR

_{L}in figure 2.
3. State superposition theorem.

4. Define power factor.

5. List few applications of diode.

6. What are the operating modes of
JFET?

7. What are the features of capacitor
filter?

8. Draw the equivalent circuit of CS
MOSFET amplifier.

9. What are the ideal characteristics
of op-amp?

10. Find the cut-off frequency of low
pass filter using op-amp.

**Part-B (5* 16 = 80 Marks)**

11. i. State Kirchoff’s current and
voltage law. (4)

ii. Find the voltage and current
through RL in figure 4. (12)

12. a. i. Convert the voltage source
given in figure 5 to current source. (4)

ii. Find the Thevenin equivalent circuit
for the circuit given in figure 6. (12)

**(OR)**

b. i . Find the resistance across A
and B in the circuit given in figure 7 using delta to Y-Conversion. (8)

ii. For the circuit given in figure 8,
find the value of RL for maximum power transfer. (8)

13. a. i. Explain the operation of
zener diode voltage regulator. (8)

ii. Draw and explain h parameter model
of BJT. (8)

**(OR)**

b. Explain the drain current flow in
depletion mode and enhancement mode MOSFET for various values of Vgs

14. a. Derive the ripple factor, TUF,
PIV and efficiency of bridge rectifier with neat circuit diagram and
input/output waveforms.

**(OR)**

b. i. With equivalent circuit diagram,
derive gain, input and output impedance of CE amplifier.

15. a. Explain the following op-amp
applications.

i. Inverting and non-inverting
amplifier (8)

ii. Subtractor (4)

iii. Integrator (4)

**(OR)**

b. With neat diagram, explain the
operation of digital to analog converter.

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