The basic electrical engineering course for first-year students

Theory & practical implementation

This basic electric engineering course is common to first-year branches of studying. At the end of the course the student is expected to know the fundamental of electrical engineering as well as the practical implementation of fundamental theory concepts.

Students will learn strong basics of Electrical Engineering and practical implementation of Electrical fundamentals. They’ll also learn different applications of commonly used electrical machinery.

Unit 1 – Basic Laws

Basic Laws: Ohm’s law, Kirchhoff’s voltage and current laws, Nodes-Branches and loops, Series elements and Voltage Division, Parallel elements and Current Division, Star-Delta transformation, Independent sources and Dependent sources, source transformation.

OHM’S LAW: At constant temperature, the current flowing through a conductor is directly proportional to the potential difference(p.d) in volts across the two ends of the given conductor and inversely proportional to the resistance (R) in ohms (Ω) between the ends of the same conductor.

In all practical problems of electrical calculations, it is assumed that the temperature rise is within limits, so that electrical properties such as insulation and conduction properties of the given material are not destroyed. Hende, Ohm’s law is mathematically stated as:

I = V/R or V=R×I or R=V/I

KIRCHOFF’S CURRENT LAW: KCL states that the total current entering a junction is equal to the total current leaving the junction, or

The algebraic sum of the currents at the junction (node) will be zero. At node n, (2 + 3 + 4) = (1 + 6 + 5) Or 2 + 3 + 4 − 1 − 6 − 5 = 0.

KIRCHOFF’S VOLTAGE LAW: KVL is based on the law of the law of conservation of the energy, states that the algebraic sum of voltage drops in a closed loop is zero.

e1 + e2 + e3 = V

e1 + e2 + e3 − V = 0

Flow of currents in loop is assumed +ve from higher potential to lower potential in elements and +ve from lower to higher potential in Sources.

Unit 2 – AC Fundamentals I

AC Fundamentals-I: Reviews of Complex Algebra, Sinusoids, phasors, Phasor Relations of circuit elements, Impedance and admittance, Impedance Combinations, Series and Parallel combination of inductors and capacitors, Mesh analysis and Nodal analysis.

Review of Complex Number:

In order to analyze AC circuit, it is necessary to represent multi-dimensional quantities. In order to accomplish this task, scalar numbers were abandoned and complete numbers were used to express the two dimensions of frequency and phase shift at one time.

In mathematics, ‘i’ is used to represent imaginary numbers. In the study of electricity and electronics, j is used to represent imaginary numbers so that there is no confusion with I, which in electronics represents current (i). It is also customary for scientist to write the complex number in the form of + .

Generation of sinusoidal AC voltage

Consider a rectangular coil of N turns placed in a uniform magnetic field as shown in the figure. The coil is rotating in the anticlockwise direction at an uniform angular velocity of ω rad/sec.

When the coil is in the vertical position, the flux linking the coil is zero because the plane of the coil is parallel to the direction of the magnetic field. Hence at this position, the emf induced in the coil is zero. When the coil moves by some angle in the anticlockwise direction, there is a rate of change of flux linking the coil and hence an emf is induced in the coil according to Faradays Law.

After that the same cycle repeats and the emf is induced in the opposite direction. When the coil completes one complete revolution, one cycle of AC voltage is generated.

Unit 3 – AC Fundamentals II

AC Fundamentals-II: RMS and average values, Form factors, Steady state Analysis of series, Parallel and Series Parallel combination of R,L,C with Sinusoidal excitation, Instantaneous power, Real power, Reactive power and Apparent power, concept of Power factor, Frequency.

Unit 4 – Network Theorems and Resonance

Network Theorems and Resonance: Superposition theorem, Thevinin’s theorem, Nortorn’s theorem, Maximum Power Transfer Theorem, Reciprocity theorem, Resonance in Electrical circuits: Analysis of series and parallel Resonance.

Unit 5 – Fundamentals of Electrical Machines

Fundamentals of Electrical Machines: Construction, Principle, Operation and Application of (i) Single phase Transformer (ii) Single phase Induction motor (iii) DC Motor.