B.Tech II Year I Semester (R15) Supplementary Examinations May/June-2019

ELECTRONIC DEVICES AND CIRCUITS

(Common to ECE & EIE)

Time: 3 hours                                                                                                      Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)
       2. Answer ALL the question in Part-A
       3. Answer any THREE questions from Part-B

PART – A

(22 Marks)

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1. a) Define drift and diffusion currents.
   b) Explain transition capacitance.
   c) Draw the circuit of full wave rectifier with inductor filter.
   d) Define h-parameters of a transistor in CE configuration.
   e) Explain thermal runaway.
   

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   f) Draw the circuit diagram of a RC phase shift oscillator.

PART – B

(3 x 16 = 48 Marks)

2. Explain about construction and working principle of PN diode and derive the current equation of the diode.

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3. Draw the circuit diagram of bridge rectifier and explain its operation. Derive the expressions for RMS voltage, DC voltage, ripple factor, efficiency and TUF.

4. Draw the circuit diagram of transistor in CE configuration and explain its input and output characteristics.

5. Explain the need of biasing. Briefly describe different biasing methods.

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6. Explain the Barkhausen criteria for oscillations. Draw the circuit diagram of Colpitts oscillator and explain its operation.

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