(SEM I) THEORY EXAMINATION 2023-24 FUNDAMENTALS OF ELECTRICAL ENGINEERING

This examination paper evaluates students’ conceptual understanding and analytical skills in fundamental electrical engineering topics, including circuit analysis, AC fundamentals, machines, transformers, power systems, and electrical safety. The paper is divided into three structured sections (A, B, and C) to test knowledge ranging from basic definitions to applied numerical problems and derivations.

SECTION A — Short Answer Questions (2 × 7 = 14 Marks)

This section contains seven compulsory short questions, each aimed at testing foundational knowledge.

Topics Covered:

1. Basic Electrical Sources & Elements

Difference between ideal and practical voltage sources

Unilateral vs bilateral elements

Active vs passive elements

2. AC Circuit Concepts

Average power consumed by a pure inductor

Resonant frequency and Q-factor of series RLC circuit

3. Magnetic & Electromagnetic Concepts

Inductance calculation from rate of change of current

4. Electrical Machines

Role of slip rings in 3-phase induction motors

5. Electrical Installation

Common problems in wiring and electrical installation systems

This section evaluates conceptual clarity and basic definitions.

SECTION B — Descriptive Questions (7 × choose any 3 = 21 Marks)

Students must attempt any three questions. These questions require explanation, circuit analysis, calculations, and reasoning.

Topics Covered:

1. Network Analysis

Current calculation using nodal analysis

Understanding of DC and AC circuit principles

2. Waveform Characteristics

Form factor and peak factor for half-wave rectified signal

3. Transformer Performance

Efficiency at full load (0.8 pf lagging) and at half load (unity pf)

Iron loss and copper loss considered

4. Induction Motor

Working principle

Torque-slip characteristics

5. Batteries

Primary and secondary batteries

Working principle of a specific secondary battery (e.g., lead-acid battery)

This section tests students’ analytical and explanatory approach with numerical and descriptive methods.

SECTION C — Long Answer Questions (7 marks each)

Each block contains two questions. Students must attempt one from each block.

Question 3 – Mesh & Nodal Analysis

3(a) Numerical Analysis

Calculate current across a given resistor using

Mesh Analysis (loop currents)

Nodal Analysis (node voltages)

3(b) Theory Question

Procedure of mesh analysis with an example
Evaluates understanding of fundamental network theorems and analysis methods.

Question 4 – AC Circuits & Three-Phase Systems

4(a) Bandwidth & Resonance

Derivation of expressions for:

Bandwidth

Upper half-power frequency

Lower half-power frequency

4(b) Three-Phase Star Circuit

Relation between line and phase voltages

Calculation of:

Line current

Power factor

Active and reactive power

Tests AC circuit theory, three-phase analysis, and formula derivation skills.

Question 5 – Transformers

5(a) Transformer Equivalent Circuit

Calculate:

Equivalent resistance and reactance referred to primary

Total copper loss

5(b) Phasor Diagram

Ideal vs practical transformer at no-load

Drawing and interpretation

Focus: transformer theory, modeling, and phasor representation.

Question 6 – DC Machines & Single-Phase Motors

6(a) DC Shunt Motor Torque & Speed

Torque equation derivation

Numerical speed calculation using given parameters

6(b) Single-Phase Induction Motor

Why it is not self-starting

Starting methods (capacitor start, split-phase, shaded pole)

Explain one method in detail

Assesses understanding of machine theory and mechanical-electrical relationships.

Question 7 – Electrical Safety & Protection

7(a) Safety Devices

Explanation with diagrams:

Earth Leakage Circuit Breaker (ELCB)

Miniature Circuit Breaker (MCB)

7(b) Earthing & Grounding

Difference between earthing and grounding

Different methods of earthing:

Plate earthing

Pipe earthing

Rod earthing

This section focuses on practical electrical installation and safety systems.

Overall Purpose of the Question Paper

This examination evaluates the student’s ability to:

Understand fundamental electrical laws and elements
Apply circuit analysis techniques (nodal, mesh, AC analysis)
Analyze transformer and machine performance
Interpret waveforms and AC characteristics
Perform calculations for power, efficiency, and resonance
Understand transformer and motor working principles
Demonstrate knowledge of electrical safety systems

The question paper ensures that engineering students develop a strong and practical foundation in electrical engineering, preparing them for more advanced subjects like power systems, electrical machines, and control systems.