About this previous year paper
This question paper aims to assess students’ understanding of basic analog electronics, digital electronics, semiconductor devices, operational amplifiers, and communication engineering fundamentals. The exam is divided into three sections (A, B, and C) to evaluate conceptual clarity, analytical skills, programming in Boolean logic, circuit interpretation, and communication system fundamentals.
SECTION A — Short Answer Questions (2 × 7 = 14 Marks)
This section evaluates foundational knowledge of electronics through seven brief questions.
Topics Covered:
1. Semiconductor Devices
Difference between P–N junction diode and LED
Why BJT is a current-controlled device
JFET vs MOSFET comparison
2. Digital Electronics
Binary addition of fractional numbers
Boolean function simplification using Boolean algebra
3. Analog Electronics
Concept of virtual ground in op-amp
Applications of satellite communication
This section checks the student’s ability to explain core concepts in concise form.
SECTION B — Descriptive Questions (7 × choose any 3 = 21 Marks)
Students must attempt any three questions, each requiring explanation, diagrams, calculations, or conversions.
Topics include:
1. Diode Characteristics
Static vs dynamic resistance
Transition vs diffusion capacitance
2. BJT Working
Working of PNP transistor in CB configuration
Input/output characteristic curves
3. Differential Amplifier & CMRR
Concept of common-mode rejection ratio
Output voltage calculation based on gain and CMRR
4. Number System & Digital Design
Conversions:
Decimal to binary
Binary to decimal
Hexadecimal to octal
2’s complement subtraction
Designing AND, OR, NOT using NOR gates (universal gate concept)
5. Communication System
Need and purpose of modulation
This section tests analytical thinking, problem solving, numerical conversions, and circuit understanding.
SECTION C — Long Answer Questions (7 marks each)
Each block contains two questions; the student must attempt one question from each block.
Question 3 — Field Effect Transistors
3(a) N-channel JFET
Requires:
Construction
Working principle
Drain and transfer characteristics
3(b) P-channel Depletion MOSFET
Requires:
Device structure
Working
Transfer and output characteristics
Focus: device physics and graph interpretation.
Question 4 — Network Output Analysis
Students must determine and draw output waveform for a given electronic network, evaluating:
Circuit understanding
Input-output relationship
Waveform drawing ability
This block assesses circuit analysis and waveform interpretation skills.
Question 5 — Operational Amplifiers
5(a) OP-Amp Subtractor
Circuit diagram
Principle of differential subtraction
Output voltage derivation
5(b) Network Output Calculation
Requires analyzing an OP-amp or linear circuit to calculate output.
Focus: analog circuit design & equations.
Question 6 — Digital Circuit Design Using K-Map
6(a) SOP Form Simplification
Simplify using K-map
Implement using only NAND gates
6(b) POS Form Simplification
Minimize Boolean function
Implement using only NOR gates
This tests:
K-map mastery
Universal gate implementation
Simplified digital logic design
Question 7 — Communication Engineering
7(a) AM Theory Derivation
Derive expressions for:
Sideband amplitude
Sideband frequencies
Modulation index
Modulation efficiency
7(b) Short Notes
Amplitude modulation technique
Radar communication basics
This section evaluates understanding of modulation, frequency analysis, and communication fundamentals.
Overall Purpose of the Question Paper
This exam is designed to ensure students develop a strong foundation in:
Semiconductor device concepts
Transistor operation and characteristics
OP-amp basics and applications
Digital logic fundamentals and number system conversions
K-map simplification and universal gate implementation
Analog and digital circuit analysis
Basic communication engineering principles
The paper tests both theoretical knowledge and practical analytical skills, preparing students for advanced electronics, digital communication, and circuit design courses.