(SEM II) THEORY EXAMINATION 2018-19 ELECTRICAL ENGINEERING

B.Tech (Semester II) | Theory Examination
Full Description of Question Paper (Long & Detailed)**

This document presents the complete and official Electrical Engineering (KEE-201) Theory Examination Question Paper for B.Tech Semester II, Total Marks: 100, Time: 3 Hours. The paper thoroughly evaluates a student's foundational understanding of electrical circuits, transformers, machines, power systems, basic protection devices, and essential electrical engineering concepts.

The structure of the question paper ensures a balanced assessment across definitions, conceptual clarity, numerical problem-solving, and applied engineering analysis.

 SECTION A – Short Answer / Conceptual Questions (20 Marks)

This section contains 10 brief questions of 2 marks each, designed to test the student’s grasp of basic principles. Topics include:

Core Concepts Covered

Purpose of Earthing electrical appliances

Various 3-phase transformer connections (Star-Star, Delta-Delta, Star-Delta, etc.)

Why a transformer cannot operate on DC

Difference between primary & secondary batteries

Meaning of active vs. passive circuit elements

Star–Delta conversion

Phase angle in a purely capacitive circuit

Calculation of speed of a 3-phase induction motor

Condition for series resonance

Applications of synchronous motors

These conceptual questions ensure the student understands basic definitions and can express them clearly and concisely.

SECTION B – Descriptive / Numerical Questions (30 Marks)

Attempt any 3 (each 10 marks)

This section tests analytical ability, numerical accuracy, and engineering explanation skills.

Topics include:

Star–Delta Relationships

Derivation of the mathematical relationship between Delta and Star connected systems.

Power in Resistive AC Circuits

Students must derive average power formulas and draw phasor and waveform diagrams.

Transformer Numerical (Heavy Weightage)

A detailed numerical problem involving:

Equivalent resistance (primary ↔ secondary)

Equivalent reactance

Total impedance

Copper losses

Torque–Slip Characteristics of Induction Motor

Explanation and sketch of torque vs. slip curve
(starting torque, maximum torque, breakdown torque).

Protection Devices

Explanation of:

MCB

ELCB

MCCB

These questions test deeper understanding and the ability to connect concepts with real engineering systems.

SECTION C – Long Answer / Application-Based Questions (40 Marks)

Four sets; attempt one from each. Each carries 10 marks.

This section focuses on problem solving, derivations, and real-world application.

Set 1 – Network Theorems

Thevenin’s theorem (finding current through a resistor)

Superposition theorem with multi-source circuit

Set 2 – Electrical Machines

Why a single-phase induction motor is NOT self-starting

Explanation of:

Split-phase method

Capacitor-start

Capacitor-run

Shaded-pole

OR numerical on DC shunt motor
(Back EMF, generated EMF when used as generator)

Set 3 – Resonance / Three Phase System

Derivation of half-power frequencies, bandwidth, Q-factor in a series RLC circuit

OR three-phase load numerical:

Line current

Power factor

Total power

Reactive volt-amp

Volt-ampere rating

Set 4 – Transformer / Efficiency

Construction, advantages, disadvantages of an Autotransformer

OR transformer efficiency numerical:

Full load, half load

Lagging PF

Maximum efficiency condition

Set 5 – Batteries / Cables (Electrical Engineering Applications)

Electrical characteristics of Lead-Acid Battery

OR construction, rating & applications of wires and cables

These long-form questions check whether students can practically apply formulas, understand machine behavior, and solve engineering problems with proper methodology.

 Sample Questions (from the actual paper)

To show the style and depth, here are two real sample questions directly from the exam:

Sample 1 (Section A):

“Define the purpose of Earthing the electrical appliances.”

Sample 2 (Section C):

“Derive half power frequencies, bandwidth and quality factor for series resonance occurring in a series RLC circuit.”

These reflect the mix of concise conceptual checks and deep analytical derivations present throughout the paper.

Overall Coverage of the Question Paper

This examination comprehensively tests a student’s knowledge across critical areas of electrical engineering:

Network Theory

Star–Delta conversions

Thevenin & Superposition Theorems

AC/DC analysis

AC Fundamentals

Resonance

Average power

Phasor diagrams

Electrical Machines

Transformers (equivalent circuits, losses, efficiency)

Induction motors (slip, torque characteristics)

DC motors & generators

Power Systems & Protection

Earthing

MCB, ELCB, MCCB

3-phase systems

Batteries & Cables

Lead-acid battery characteristics

Types of cables and applications

The structure ensures a balanced evaluation of definitions, theory, numericals, applications, and engineering diagrams.