About this previous year paper
This document is the B.Tech Semester III Theory Examination 2019–20 question paper for Electronic Devices (Sub Code: KEC301) under Dr. A.P.J. Abdul Kalam Technical University (AKTU).
The uploaded file contains two pages and is structured into three sections: SECTION A, SECTION B, and SECTION C.
The exam carries 100 marks and the duration is 3 hours.
The paper assesses the student's understanding of semiconductor physics, MOSFETs, BJTs, avalanche breakdown, fluorescence, carrier transport, lifetime, drift/diffusion mechanisms, Schottky diode, Ebers–Moll model, LED/Solar cell, and diode current equation.
SECTION A — Short Questions (10 × 2 = 20 Marks)
(Visible on Page 1 of the document)
Section A includes ten 2-mark questions that test fundamental knowledge of solid-state devices and semiconductor concepts.
The questions include:
Base width modulation
Direct vs Indirect semiconductors
Differences between EMOSFET and DMOSFET
Avalanche breakdown mechanism
BJT as a switch/amplifier
Fluorescence
Effective mass of carriers
Direct vs indirect recombination lifetime
Drift vs diffusion
Sheet resistance
These are direct conceptual questions presented in a table format on Page 1.
SECTION B — Long Answer Questions (Attempt Any 3 × 10 = 30 Marks)
(Located on Page 1)
Section B contains five descriptive questions, out of which students must attempt any three.
Topics include:
Direct and indirect bandgap semiconductors
PN junction diode characteristics
Working of N-channel MOSFET
Construction and characteristics of LED & Solar cell
Avalanche breakdown and related mechanisms
These questions require diagrams, characteristics curves, and proper theoretical explanations.
SECTION C — Advanced / Application-Based Questions (Q5–Q7)
(Shown on Page 2)
Section C contains three main questions (Q5, Q6, Q7), each having two alternatives (a or b).
Students must attempt one part from each question number.
Q5 — MOSFET Model / Optoelectronic Devices
(a) Explain & draw small-signal models of MOS transistor
OR
(b) Working principle & characteristics of LED and Solar Cell
Q6 — Ebers–Moll / Schottky Diode
(a) Explain Ebers–Moll model
OR
(b) Explain Schottky diode, construction & applications
Q7 — Continuity Equation / Diode Equation
(a) Derive continuity equation & diffusion length
OR
(b) Derive diode current equation for PN junction
These questions involve derivations, models, and deeper device physics understanding.
OVERALL SUMMARY OF THE DOCUMENT
The Electronic Devices (KEC301) question paper evaluates a student’s understanding of:
Semiconductor fundamentals
MOSFET operation & models
BJT working principles
Breakdown mechanisms
Drift & diffusion of carriers
Recombination processes
Optoelectronic devices: LED, Solar cell
Ebers–Moll transistor model
Schottky diode
Continuity equation
Diode current equation
The paper strictly follows the AKTU 3-section structure:
SECTION A: Quick conceptual recall
SECTION B: Descriptive theory & device explanations
SECTION C: Derivations, models, and advanced semiconductor analysis
The uploaded file contains two clearly readable pages with all questions properly organized.