Electronic Devices (EC-304) - Important Questions

Write short note on Schottky diode

Explain tunnelling, construction, working, V-I characteristics and equivalent circuit of tunnel diode

Draw and explain the construction, working, characteristics and tunnelling phenomenon of varactor diode

Explain intrinsic vs extrinsic semiconductors, including n-type and p-type and how they are obtained

Describe the energy band structure of insulators, semiconductors and conductors

Determine the temperature coefficient of a 5V Zener diode at $25^\circ\text{C}$ dropping to $4.8\text{V}$ at $100^\circ\text{C}$.

Describe the V-I characteristics of a Zener diode and explain its working/applications.

State the law of the junction for injected minority carrier concentration versus applied voltage and explain how avalanche breakdown voltage varies with temperature.

Briefly discuss LED and solar cell, and Zener diode as voltage regulator

Determine thermal equilibrium electron and hole concentrations from given donor, acceptor and intrinsic concentrations.

Explain the construction and working of a Zener diode with circuit diagram.

Explain energy bands and equilibrium condition in semiconductors

Explain the working principle of clipper and clamper circuits with circuit diagrams.

Describe/explain the working of half-wave and full-wave / bridge rectifier circuits with diagrams

Write short notes on any two the following:

Explain the working of bridge rectifier and derive expressions for RMS current, PIV, ripple factor and efficiency

Determine and sketch the output voltage for a given clipper/clamper network.

What is a voltage regulator? Explain voltage regulation using series regulator circuit in detail.

Compare the ideal and practical diode with their advantages and disadvantages.

Explain the working of half-wave rectifier with neat sketch and derive its characteristics

Determine transformer rating to deliver given DC power for half-wave rectifier and full-wave rectifier

Numerical on half-wave rectifier with transformer: find DC output voltage and PIV for given AC supply and turns ratio

Explain the operation/working of full-wave rectifier with circuit diagram and waveforms

Derive the expression for ripple factor of a full-wave rectifier with L-section (LC) filter.

What is biasing, what is the need of biasing, and what are the different biasing techniques for BJT?

For a CE NPN transistor with given $V_{CC}, V_{BB}, I_C, V_{CE}, V_{BE}$, find $\beta$ and base resistor $R_B$.

Explain the selection of Q-point for transistor biasing and the limitations on output voltage swing

Design a voltage-divider bias circuit to establish a given Q-point $V_{CE}, I_C$ with given stability factor, $\beta$ and $V_{CC}$.

Define phototransistor and explain the various configurations of BJT.

Explain any one biasing technique of BJT with suitable diagram.

Explain why common-collector mode is generally not preferred and determine dynamic output resistance from change in $V_{CE}$ and $I_C$.

Describe the construction and working of a PNP transistor in common-base configuration.

Explain the fixed bias and self-bias (emitter bias) circuits of a transistor.

Deduce the transistor current equation from the transistor current components.

Write short note on DC and AC load lines and transistor as a switch

In a self-bias circuit containing $R_1 = 50\text{K}\Omega$, $R_2 = 25\text{K}\Omega$, $R_E = 1\text{K}\Omega$, $R_C = 3\text{K}\Omega$, $\beta = 90$, $V_{CC} = 12\text{V}$, $V_{BE} = 0.7\text{V}$. Find the operating point, $S, S'$.

Describe / explain class A and class B amplifiers with neat diagram.

Derive the analysis of a common-emitter / transistor amplifier using h-parameters (voltage gain, current gain, input/output impedance).

Determine the h-parameters for CE configuration from the transistor characteristic curves.

Explain the Darlington amplifier circuit with diagram and list its applications.

Describe the current mirror circuit with diagram / short note, including push-pull amplifier where asked.

Explain the coupling methods used in multistage amplifiers.

Explain the reasons for gain fall at low and high frequencies and why the Miller effect is reduced in a cascade amplifier.

Analyze the V-I characteristics, output resistance, minimum sustainable voltage and maximum usable load of a current mirror.

What is harmonic distortion, how does it arise in Class B operation, and how is it corrected in a push-pull circuit?

Explain the class B power amplifier circuit in detail.

Explain the bootstrapping technique and the current mirror circuit in brief.

Explain the need and working of the bootstrapping circuit with a neat diagram.

Explain the construction and working principle of operation of UJT including its equivalent circuit and V-I characteristics.

Explain the construction and working of JFET with neat diagram.

Explain the working principle of an n-channel depletion-type MOSFET and describe its characteristics with diagrams.

Describe small-signal NMOS MOSFET amplifiers and obtain the expression for transconductance.

Derive the voltage gain expression for a common-source (CS) MOSFET amplifier using the small-signal hybrid-\pi model at low frequencies.

Write short notes on pinch off voltage, tunnel diode, clipper and clamper, and class A amplifier.

Calculate $I_D$ and $g_m$ for given $V_{GS}$, $I_{DSS}$ and $V_p$.

Explain the Thyristor, its principle of operation and applications.

Draw the equivalent circuit of a MOSFET operating in enhancement mode.

What is UJT and explain its operation as a relaxation oscillator.

Explain the voltage divider biasing method for FET/JFET with a neat diagram (including different biasing schemes).

Describe transfer and drain characteristics of JFET and MOSFET, UJT and Thyristors, and CS and CG configurations with neat diagrams.