THEORY EXAMINATION (SEM–II) 2016-17 BASIC ELECTRONICS

This document contains the complete B.Tech Electronics Engineering / Basic Electronics Semester Examination question paper, designed for 70 marks with a duration of 3 hours. The paper evaluates a student’s understanding of semiconductor devices, electronic circuits, operational amplifiers, digital measuring instruments, and communication fundamentals. It is divided into three well-structured sections (A, B, and C), ensuring coverage of both theoretical knowledge and analytical problem-solving skills.

SECTION – A (Short Conceptual Questions – 7 × 2 = 14 Marks)

Students must attempt any seven out of the given eight questions. These short questions focus on basic principles, definitions, and conceptual clarity on key topics such as:

Classification of materials into conductors, semiconductors, and insulators using energy band diagrams

Basic operation and principle of Light Emitting Diode (LED)

Derivation of the relationship between α (alpha) and β (beta) in BJTs

Reason why FETs are called unipolar devices

Constructional differences between Depletion MOSFET and Enhancement MOSFET

Derivation of integrator circuit using an ideal operational amplifier

Advantages of digital instruments over analog instruments

Need and importance of modulation in communication engineering

These questions help evaluate foundational understanding of electronic components and circuits.

SECTION – B (Analytical & Descriptive Questions – 5 × 7 = 35 Marks)

Students must attempt any five out of eight questions. This section requires detailed explanations, device characteristics, waveforms, derivations, and circuit analysis.

Key topics include:

Semiconductor Diodes

Explanation of V–I characteristics of a p-n junction diode

Comparison between p-n diode and Zener diode

Rectifiers

Construction and working of a full-wave bridge rectifier

Input and output waveforms

Calculation of Peak Inverse Voltage (PIV)

MOSFET Characteristics

Construction and working of p-channel depletion MOSFET

Transfer and drain characteristics with diagram

Op-Amp Circuits

Calculation of output voltage from a given op-amp circuit

Understanding superposition of inputs

Transistor Biasing

Determination of R₁ and R_C for given biasing conditions (ICQ, VCEQ)

Digital Instruments

Block diagram and working of Ramp Type Digital Voltmeter (DVM)

Voltage-to-time conversion waveforms

Communication Engineering

Derivation of AM modulated waveform

Derivation of modulation index

Cathode Ray Oscilloscope (CRO)

Block diagram and operation of CRT

Measurement of unknown frequency using Lissajous figures in CRO

This section tests practical electronic circuit knowledge, math-based analysis, and application of theories.

SECTION – C (Long Answer Questions – 2 × 10.5 = 21 Marks)

Students must attempt any two out of three detailed questions. These questions require deeper explanation, device characteristics, and complete circuit understanding.

Q3 – Tunnel Diode & Clamper Design

Principle and construction of Tunnel Diode

Its unique negative resistance region and V–I characteristics

Designing a clamper circuit to achieve the waveform shown in the question

Q4 – JFET & Differential Amplifier

Construction and operation of N-Channel JFET

Transfer characteristics (ID vs VGS)

Block diagram and working of a differential amplifier

Definitions of CMRR and slew rate of operational amplifiers

Q5 – BJT Characteristics & Modulation

Input and output characteristics of CE n-p-n transistor configuration

Explanation of self-biasing technique

Need for modulation in communication systems

Types of modulation used in television broadcasting (AM, FM, PM)

This section measures high-level understanding of electronic devices, communication concepts, and analog circuit design.