Saturday, 31 January 2015

Electronic Devices and Circuits Important Questions

Electronic Devices and Circuits Important Questions
EDC Important Questions External Exams

Unit 1

1.Draw the circuit diagram and explain the working of full wave bridge rectifier and derive the expression for average output current and rectification efficiency.
2.With a neat diagram explain the working of a PN junction diode in forward bias and reverse bias and show the effect of temperature on its V-I characteristics.
3.Explain V-I characteristics of Zener diode
4.Derive the diode equation of the diode
5.Explain Zener diode and it’s breakdown mechanism?

Unit 2

1. Sketch neatly the circuit diagram of a CE configuration transistor, discuss its operation, characteristics and compare it with other modes of operation.
2. Derive the hybrid model of a CE Amplifier.
3. What are Power Transistors?
4. Describe the methods of determining h-parameters from its static input and output characteristics.
5. Derive the equation for efficiency of a Class B amplifier

Unit 3

1. Discuss in detail the working and operation of JFET and explain the I/O characteristics
2. Explain the operation and Characteristics of Enhancement mode MOSFET & Depletion mode MOSFET
3. Explain how the transconductance of a JFET varies with drain current and gate voltage characteristics and transfer characteristics
4. In a JFET the following parameters are given, IDDS = 32Ma, VG(off) = -8V and VGS = 4.5 V. Find The values of drain current.
5.Explain the application of FET as a voltage variable resistor

Unit 4

1. Draw the block diagram of a voltage series feedback amplifier and derive the equation for input impedance, output impedance and the voltage gain.
2. Differentiate oscillator with amplifier
3. Draw the circuit of a Hartley oscillator and derive the condition for the frequency of oscillation.
4. Explain the working of a differential amplifier in both common and differential mode.
5. Explain the operation of any one type of oscillator in detail and give its equation.

Unit 5

1. Draw the circuit diagram of a collector coupled astable multivibrator using complementary transistors and draw the typical wave form at base and collector coupled astable multivibrator.
2. Explain the working and operation of a Schmitt trigger with a neat diagram.
3. Explain the working and operation of a UJT saw tooth oscillator with a neat diagram.
4. Explain the working and operation of a Monostable MV with a neat diagram.
5. Explain the operation of a Bistable MV with a neat sketch.