Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option/answer the following (Any seven question
only):
Which of the following best describes the energy band model of a semiconductor?
In an extrinsic semiconductor at equilibrium, the Fermi level $E_F$ shifts towards:
Which of the following phenomena describe the generation and recombination processes in semiconductors?
What is the primary cause of the built-in potential in a PN junction diode?
Which of the following mechanisms is responsible for junction breakdown in a Zener diode?
In which mode of operation does a Bipolar Junction Transistor (BJT) act as an amplifier?
What is the expression for common-base current gain ($\alpha$) of a BJT?
In a Junction Field-Effect Transistor (JFET), the drain current ($I_D$) in the saturation region is primarily controlled by:
Which of the following correctly describes the threshold voltage ($V_{th}$) of a MOSFET?
Which of the following devices is primarily used for triggering other semiconductor devices like SCRs?
Q.2 Solve both questions :
Explain the concept of the bonding model and energy band model in semiconductors.
Explain drift and diffusion current mechanisms in semiconductors. Derive the Einstein relation that connects diffusion coefficient and mobility.
Q.3 Solve both questions :
Discuss the different types of recombination mechanisms and their significance in semiconductor devices.
Write and explain the continuity equation for charge carriers in semiconductors. Derive the minority carrier diffusion equation and discuss its importance in the operation of semiconductor devices.
Q.4 Solve both questions :
Explain the Ideal Diode Equation. Derive it quantitatively using the band model and boundary conditions, stating the assumptions made in the derivation.
Explain the working principles and applications of special diodes such as the Zener diode, Tunnel diode, Varactor diode and Schottky diode. How do their characteristics differ from a conventional PN junction diode?
Q.5 Solve this question :
Discuss the two primary mechanisms of junction breakdown in a PN junction diode- Avalanche breakdown and Zener breakdown. Compare their occurrence conditions and characteristics.
Q.6 Solve this question :
Describe the impact of base width modulation (Early effect) on BJT operation. How does it affect the common-emitter current gain and output characteristics? Include relevant equations in your explanation.
Q.7 Solve this question :
Explain the deviations from ideal MOS behaviour, including metal-semiconductor work function differences, fixed oxide charges, interface traps and threshold voltage shifts. How do these non-ideal effects influence MOSFET performance?
Q.8 Solve this question :
Discuss the working principles and characteristics of different optoelectronic devices: PIN Photodiode, Avalanche Photodiode, Solar Cell and LED. Compare their applications.
Q.9 Solve this question :
Explain the working of a solid-state laser diode. How does it differ from an LED in terms of construction, working principle, and applications? Discuss its advantages in optical communication.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct option/answer the following (Any seven question
only):
Which of the following best describes the energy band model of a semiconductor?
In an extrinsic semiconductor at equilibrium, the Fermi level $E_F$ shifts towards:
Which of the following phenomena describe the generation and recombination processes in semiconductors?
What is the primary cause of the built-in potential in a PN junction diode?
Which of the following mechanisms is responsible for junction breakdown in a Zener diode?
In which mode of operation does a Bipolar Junction Transistor (BJT) act as an amplifier?
What is the expression for common-base current gain ($\alpha$) of a BJT?
In a Junction Field-Effect Transistor (JFET), the drain current ($I_D$) in the saturation region is primarily controlled by:
Which of the following correctly describes the threshold voltage ($V_{th}$) of a MOSFET?
Which of the following devices is primarily used for triggering other semiconductor devices like SCRs?
Q.2 Solve both questions :
Explain the concept of the bonding model and energy band model in semiconductors.
Explain drift and diffusion current mechanisms in semiconductors. Derive the Einstein relation that connects diffusion coefficient and mobility.
Q.3 Solve both questions :
Discuss the different types of recombination mechanisms and their significance in semiconductor devices.
Write and explain the continuity equation for charge carriers in semiconductors. Derive the minority carrier diffusion equation and discuss its importance in the operation of semiconductor devices.
Q.4 Solve both questions :
Explain the Ideal Diode Equation. Derive it quantitatively using the band model and boundary conditions, stating the assumptions made in the derivation.
Explain the working principles and applications of special diodes such as the Zener diode, Tunnel diode, Varactor diode and Schottky diode. How do their characteristics differ from a conventional PN junction diode?
Q.5 Solve this question :
Discuss the two primary mechanisms of junction breakdown in a PN junction diode- Avalanche breakdown and Zener breakdown. Compare their occurrence conditions and characteristics.
Q.6 Solve this question :
Describe the impact of base width modulation (Early effect) on BJT operation. How does it affect the common-emitter current gain and output characteristics? Include relevant equations in your explanation.
Q.7 Solve this question :
Explain the deviations from ideal MOS behaviour, including metal-semiconductor work function differences, fixed oxide charges, interface traps and threshold voltage shifts. How do these non-ideal effects influence MOSFET performance?
Q.8 Solve this question :
Discuss the working principles and characteristics of different optoelectronic devices: PIN Photodiode, Avalanche Photodiode, Solar Cell and LED. Compare their applications.
Q.9 Solve this question :
Explain the working of a solid-state laser diode. How does it differ from an LED in terms of construction, working principle, and applications? Discuss its advantages in optical communication.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Write the short answer of the following (Any seven question
only):
Define the term drift velocity.
Define Fermi energy level.
Define doping process.
Why is the width of the base region kept very small as compared to other regions in BJT's?
Write the difference between Zener and Avalanche breakdown.
What do you mean by solid state?
Define the effective mass and express it in terms $(E, K)$.
Define conductivity and mobility.
Write two differences between BJT and FET.
Define the varactor diode.
Q.2 Solve both questions :
Explain (i) Solar Cell (ii) LED (iii) LASER diode.
Discuss the working principle of SCR. How it is different from UJT?
Q.3 Solve both questions :
What is MOS Capacitor? Draw its C-V Characteristic.
Explain the operation of enhancement mode MOSFET with neat diagram and compare it with JFET.
Q.4 Solve both questions :
Discuss the punch-through breakdown in BJT. Write the expression for the punch though voltage.
Distinguish between the different types of transistor configurations with necessary circuit diagrams.
Q.5 Solve both questions :
With a neat diagrams explain the working of a PN junction diode in forward bias and reverse bias and plot the V-I characteristics.
Discuss about the effects of temperature on PN junction diode's Forward and Reverse characteristics.
Q.6 Solve both questions :
What is Zener diode. Explain V-I characteristics of Zener diode.
When a transistor is used as a switch, in which region of output characteristics it is operated? Discuss with reason.
Q.7 Solve this question :
What is intrinsic semiconductor and explain the formation extrinsic semiconductors through doping?
Q.8 Solve both questions :
Derive the expression for current generated due to drifting of charge carriers in semiconductors in the presence of electric field.
Derive Einstein's relation in semiconductors?
Q.9 Write Short notes ver any two of the following:
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Write the short answer of the following (Any seven question
only):
Define the term drift velocity.
Define Fermi energy level.
Define doping process.
Why is the width of the base region kept very small as compared to other regions in BJT's?
Write the difference between Zener and Avalanche breakdown.
What do you mean by solid state?
Define the effective mass and express it in terms .
Define conductivity and mobility.
Write two differences between BJT and FET.
Define the varactor diode.
Q.2 Solve both questions :
Explain (i) Solar Cell (ii) LED (iii) LASER diode.
Discuss the working principle of SCR. How it is different from UJT?
Q.3 Solve both questions :
What is MOS Capacitor? Draw its C-V Characteristic.
Explain the operation of enhancement mode MOSFET with neat diagram and compare it with JFET.
Q.4 Solve both questions :
Discuss the punch-through breakdown in BJT. Write the expression for the punch though voltage.
Distinguish between the different types of transistor configurations with necessary circuit diagrams.
Q.5 Solve both questions :
With a neat diagrams explain the working of a PN junction diode in forward bias and reverse bias and plot the V-I characteristics.
Discuss about the effects of temperature on PN junction diode's Forward and Reverse characteristics.
Q.6 Solve both questions :
What is Zener diode. Explain V-I characteristics of Zener diode.
When a transistor is used as a switch, in which region of output characteristics it is operated? Discuss with reason.
Q.7 Solve this question :
What is intrinsic semiconductor and explain the formation extrinsic semiconductors through doping?
Q.8 Solve both questions :
Derive the expression for current generated due to drifting of charge carriers in semiconductors in the presence of electric field.
Derive Einstein's relation in semiconductors?