1. EE2010 Fundamentals of Electric Circuits Text Book: Introductory Circuit Analysis - Robert Boylestad

2. Course Description – Basic circuit elements and concepts. – Basic laws of circuit theory: Ohm's law, Kirchoff's laws. – Circuit theorems: superposition principle, Thevenin and Norton theorems; maximum power transfer theorem. – Techniques of circuit analysis: nodal and mesh analysis; sinusoidal sources and the concept of phasor in circuit analysis. – Introduction to concept of active, reactive, complex power and power factor.

3. The Purpose of this Course By the end of this course the student will be able to Identify and apply the concepts of DC electrical current, voltage, power, resistance, capacitance and inductance. Analyze series, parallel and combination circuits using Ohm’s law, Joule’s law, Kirchhoff’s laws, Voltage Divider rule, Current divider rule, Mesh and nodal analysis. Analyze series-parallel circuits, including bridge networks, using Thevenin, Norton, Superposition, and Maximum power Transfer. Analyze the transient response of circuits with capacitors and inductors. Identify the parameters in sinusoidal AC waveforms. Implement and test DC circuit analysis.

4. EE2010 Fundamentals of Electric Circuits Lecture - 1 Basic circuit elements and concepts

5. Atoms and their structure  Have neutrons, protons, and electrons.  Protons are positively charged  Electrons are negatively charged

6. Electrons…  Are located on the outer edges of atoms…they can be moved.  A concentration of electrons in an atom creates a net negative charge.  If electrons are stripped away, the atom becomes positively charged.

7. Atomic Structure The charge of electron is so small (- 1.602 x 10 -19 C ) Charge in motion represents a current Charge on a proton = 1.602 x 10 -19 C The Unit of Charge = Coulomb (C) 1 Coulomb of Charge is 1/ 1.602 x 10 -19 = 6.242 x 10 18 electrons The symbol for charge is Q (or) q

8. Coulomb’s Law ¤Like charges repel, opposites attract

9. 9 What is an electric current? An electric current is a flow of microscopic particles called electrons flowing through wires and components. + - In which direction does the current flow? from the Negative terminal to the Positive terminal of a cell.

10. Current The flow of electron in a conductor is called electric current The electric current (I) is defined as the time rate of change of charge I = dq/dt or I = Q/t 1 Ampere = 1 Coulomb / 1 Second I = Q/t Q = I x t t = Q/I

11. 2 types of current Direct Current (DC) – Where electrons flow in the same direction in a wire. Alternating Current (AC) – electrons flow in different directions in a wire

12. 12 Question If a laptop constantly needs 2 Amps current from a battery, how many electrons are drained from the battery in one hour? ¤1 Amp = 6.242 x 10 18 electrons/second ¤2 Amp = 12.484 x 10 18 electrons/second ¤In one hour - > 3600 x 12.484 x 10 18 electrons ¤Answer is 4.49 x 10 22 electrons

13. Voltage Electric Potential The ability of a charged particle to do the work is called as electric potential The potential difference between two points in an electric circuit called voltage The unit of voltage is volt (V) Electric potential (V) = work done/charge V = W/Q v = dw/dq 1 volt = 1 joule/coulomb Voltage or potential difference is the energy required to move a unit charge through an element

14. Resistance Resistance is proportional to length Resistance is inversely proportional to the cross sectional area R = ρ L/A ρ is the resistivity of the material (Ohm-Metres ) length direction of current flow

15. Resistors, Capacitors and Inductors Resistors provide resistance – they oppose the flow of electricity – measured in Ohms (  ) Capacitors provide capacitance – they store energy in an electric field – measured in Farads (F) Inductors provide inductance – they store energy in a magnetic field – measured in Henry (H)