JNTUH B.Tech - R25 - Electronic Devices and Circuits - Important Questions

[Rahul]

JNTUH B.Tech - R25 - Electronic Devices and Circuits - Important Questions

Unit 1 : Diode Characteristics and Applications

• Explain the construction and operation of the PN Junction Diode.
• Draw and explain the I–V characteristics of a PN junction diode.
• Define Diode Resistance and explain static and dynamic resistance.
• Explain Junction Capacitance and diffusion capacitance.
• Discuss Diode Models: ideal, simplified, and piecewise linear models.
• Draw and explain the working of the Half-Wave Rectifier.
• Draw and explain the working of the Full-Wave Rectifier using center-tap configuration.
• Draw and explain the working of the Bridge Rectifier.
• Compare half-wave and full-wave rectifiers.
• Explain the role of a Capacitor Filter in rectifier circuits.
• Define Clipper Circuit and explain its types.
• Define Clamper Circuit and explain positive and negative clampers.
• Draw and explain the I–V characteristics of the Zener Diode.
• Explain the use of a Zener diode as a Voltage Regulator.
• Compare ordinary diodes and Zener diodes with suitable applications.

Unit 2 : Bipolar Junction Transistor (BJT)

• Explain the structure and working principle of the Bipolar Junction Transistor (BJT).
• Describe the operation of NPN Transistor and PNP Transistor.
• Explain the current components in a BJT and the concept of transistor action.
• Define the current gains Alpha (α) and Beta (β) and derive the relation between them.
• Draw and explain the circuit configuration of the Common Base (CB) Configuration.
• Draw and explain the input and output characteristics of the Common Base configuration.
• Draw and explain the circuit configuration of the Common Emitter (CE) Configuration.
• Draw and explain the input and output characteristics of the Common Emitter configuration.
• Draw and explain the circuit configuration of the Common Collector (CC) Configuration.
• Draw and explain the input and output characteristics of the Common Collector configuration.
• Compare CB, CE, and CC configurations with respect to current gain, voltage gain, input resistance, and output resistance.
• Define Hybrid Parameters (h-Parameters) and explain their significance.
• Explain the determination of h-parameters from transistor characteristics.
• Derive the relationships among transistor currents IE, IB, and IC.
• Discuss the applications of different BJT configurations in electronic circuits.

Unit 3 : BJT Biasing

• Explain the need for BJT Biasing in transistor circuits.
• Define Operating Point (Q-Point) and explain its significance.
• Explain the concept of DC Load Line.
• Draw and explain the determination of the Q-point using the load line method.
• Explain the Fixed Bias Circuit and derive the expressions for collector current and stability factor.
• Explain the Collector-to-Base Bias and discuss its advantages.
• Explain the Voltage Divider Bias and derive the expressions for the operating point.
• Compare fixed bias, collector-to-base bias, and voltage divider bias.
• Define Stability Factor.
• Derive the stability factor for different biasing circuits.
• Explain the phenomenon of Thermal Runaway.
• Discuss methods to prevent thermal runaway in transistor circuits.
• Explain the role of emitter resistance in improving bias stability.
• Solve numerical problems on operating point and stability factor calculations.
• Which biasing technique provides the best stability and why?

Unit 4 : Transistor Amplifiers

• Explain the operation of a Small-Signal Amplifier using a transistor.
• Discuss the transistor as a small-signal amplifier and explain the principle of amplification.
• Define the h-Parameter Equivalent Circuit and explain its components.
• Explain the meaning and significance of h₁₁, h₁₂, h₂₁, and h₂₂ parameters in transistor analysis.
• Derive the current gain, voltage gain, input resistance, and output resistance of the Common Emitter Amplifier using h-parameters.
• Analyze the Common Base Amplifier using h-parameters.
• Analyze the Common Collector Amplifier using h-parameters.
• Compare CE, CB, and CC amplifiers based on gain and impedance characteristics.
• Explain the Approximate CE Model.
• Derive the voltage gain of a CE amplifier without an Emitter Bypass Capacitor.
• Derive the voltage gain of a CE amplifier with an emitter bypass capacitor.
• Explain the effect of emitter resistance and bypass capacitor on amplifier gain and stability.
• Draw the AC equivalent circuit of a CE amplifier and explain each component.
• Solve numerical problems on h-parameter amplifier analysis.
• Discuss the practical applications of transistor amplifiers in electronic systems.

Unit 5 : Special Purpose Diodes / Field Effect Transistors and Advanced Devices

• Explain the principle of operation and applications of the Silicon Controlled Rectifier (SCR).
• Draw and explain the V–I characteristics of the Tunnel Diode.
• Explain the construction, working, and applications of the Varactor Diode.
• Describe the operation and uses of the Photodiode.
• Explain the construction, working principle, and applications of the Solar Cell.
• Explain the construction, characteristics, and applications of the Light-Emitting Diode (LED).
• Discuss the features and applications of the Schottky Diode.
• Explain the structure and operation of the Junction Field-Effect Transistor (JFET).
• Draw and explain the drain and transfer characteristics of a JFET.
• Explain the structure, operation, and characteristics of the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET).
• Differentiate between Enhancement-Mode MOSFET and Depletion-Mode MOSFET.
• Explain the 3D structure and scaling advantages of the FinFET.
• Describe the structure, ballistic transport concept, and fabrication aspects of the Carbon Nanotube Field-Effect Transistor (CNTFET).
• Compare CMOS, FinFET, and CNTFET technologies.
• Discuss the future significance of advanced transistor technologies in nanoelectronics.