1. Introduction and Chapter Objectives
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Electric Circuit • Basic Laws – Ohm’S Law – Kirchhoff's Voltage Law – Kirchhoff's Current Law • Power and Energy
Basic Definitions & Basic Laws Dr. Mohamed Refky Amin Electronics and Electrical Communications Engineering Department (EECE) Cairo University [email protected] http://scholar.cu.edu.eg/refky/ Outline of this Lecture • Course Contents, References, Course Plan • Basic Definitions • Topology of Electric Circuit • Basic Laws – Ohm’s Law – Kirchhoff's Voltage Law – Kirchhoff's Current Law • Power and Energy Dr. Mohamed Refky 2 References • Textbook: – “Fundamentals of Electric Circuits”, Alexander and Sadiku, 5th edition • References: – J. W. Nilsson and S. Riedel, Electric Circuits. 8th Edition, Prentice Hall, 2008. – Syed A. Nasar, “Electric Circuits,” Schaum’s Solved Problems Series, Mcgraw-Hill, New York, 1988. – Cunningham Stuller, “Circuit Analysis,” John Wiley & Sons Inc., New York, 1995. Dr. Mohamed Refky 3 Course Plan • Instructor: Prof. Mohamed Fathy Dr. Mohamed Refky • TA: TBA • Grading: – 40% Activity • Quizzers • Assignments • Attendance – 20 % Midterm – 40% Final Exam • Office Hours: TBA Dr. Mohamed Refky 4 Course Contents Week Topic 1 Basic Definitions & Basic Laws 2 3 Methods of solution of DC circuits 4 8 Network Theorems 6 Midterm 7 Introduction to Capacitors and Inductors 8 Sinusoids and phasors 9 10 Sinusoidal steady state analysis 11 12 Three Phase Circuits Dr. Mohamed Refky 5 Introduction Importance of this Course For an electrical engineering student, basic electric circuit theory is an essential to understand several other courses. Many branches of electrical engineering, such as power, electric machines, electronics, and instrumentation, are based on electric circuit theory. Dr. Mohamed Refky 6 Outline of this Lecture • Course Contents, References, Course Plan • Basic Definitions • Topology of Electric Circuit • Basic Laws – Ohm’s Law – Kirchhoff's Voltage Law – Kirchhoff's Current Law • Power and Energy Dr. -
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2 February 15, 2006 . DRAFT Cambridge-MIT Institute Multidisciplinary Design Project This Dictionary/Glossary of Engineering terms has been compiled to compliment the work developed as part of the Multi-disciplinary Design Project (MDP), which is a programme to develop teaching material and kits to aid the running of mechtronics projects in Universities and Schools. The project is being carried out with support from the Cambridge-MIT Institute undergraduate teaching programe. For more information about the project please visit the MDP website at http://www-mdp.eng.cam.ac.uk or contact Dr. Peter Long Prof. Alex Slocum Cambridge University Engineering Department Massachusetts Institute of Technology Trumpington Street, 77 Massachusetts Ave. Cambridge. Cambridge MA 02139-4307 CB2 1PZ. USA e-mail: [email protected] e-mail: [email protected] tel: +44 (0) 1223 332779 tel: +1 617 253 0012 For information about the CMI initiative please see Cambridge-MIT Institute website :- http://www.cambridge-mit.org CMI CMI, University of Cambridge Massachusetts Institute of Technology 10 Miller’s Yard, 77 Massachusetts Ave. Mill Lane, Cambridge MA 02139-4307 Cambridge. CB2 1RQ. USA tel: +44 (0) 1223 327207 tel. +1 617 253 7732 fax: +44 (0) 1223 765891 fax. +1 617 258 8539 . DRAFT 2 CMI-MDP Programme 1 Introduction This dictionary/glossary has not been developed as a definative work but as a useful reference book for engi- neering students to search when looking for the meaning of a word/phrase. It has been compiled from a number of existing glossaries together with a number of local additions. -
Introduction to Electrical and Computer Engineering International
Introduction to Electrical and Computer Engineering Basic Circuits and Simulation Electrical & Computer Engineering Basic Circuits and Simulation (1 of 22) International System of Units (SI) • Length: meter (m) • SI Prefixes (power of 10) • Mass: kilogram (kg) – 1012 Tera (T) • Time: second (s) – 109 Giga (G) – 106 Mega (M) • Current: Ampere (A) – 103 kilo (k) • Voltage: Volt (V) – 10-3 milli (m) • Temperature: Degrees – 10-6 micro (µ) Kelvin (ºK) – 10-9 nano (n) – 10-12 pico (p) Electrical & Computer Engineering Basic Circuits and Simulation (2 of 22) 1 SI Examples • A few examples: • 1 Gbit = 109 bits, or 103106 bits, or one thousand million bits – 10-5 s = 0.00001 s; use closest SI prefix • 1×10-5 s = 10 × 10-6 s or 10 μs or • 1×10-5 s = 0.01 × 10-3 s or 0.01 ms Electrical & Computer Engineering Basic Circuits and Simulation (3 of 22) Typical Ranges Voltage (V) Current (A) • 10-8 Antenna of radio • 10-12 Nerve cell in brain receiver (10 nV) • 10-7 Integrated circuit • 10-3 EKG – voltage memory cell (0.1 µA) produced by heart • 10×10-3 Threshold of • 1.5 Flashlight battery sensation in humans • 12 Car battery • 100×10-3 Fatal to humans • 110 House wiring (US) • 1-2 Typical Household • 220 House wiring (Europe) appliance • 107 Lightning bolt (10 MV) • 103 Large industrial appliance • 104 Lightning bolt Electrical & Computer Engineering Basic Circuits and Simulation (4 of 22) 2 Electrical Quantities • Electric Charge (positive or negative) – (Coulombs, C) - q – Electron: 1.602 x 10 • Current (Ampere or Amp, A) – i or I – Rate of charge flow, – 1 1 Electrical & Computer Engineering Basic Circuits and Simulation (5 of 22) Electrical Quantities (continued) • Voltage (Volts, V) – w=energy required to move a given charge between two points (Joule, J) – – 1 1 1 Joule is the work done by a constant 1 N force applied through a 1 m distance. -
Electric Potential
Electric Potential • Electric Potential energy: b U F dl elec elec a • Electric Potential: b V E dl a Field is the (negative of) the Gradient of Potential dU dV F E x dx x dx dU dV F UF E VE y dy y dy dU dV F E z dz z dz In what direction can you move relative to an electric field so that the electric potential does not change? 1)parallel to the electric field 2)perpendicular to the electric field 3)Some other direction. 4)The answer depends on the symmetry of the situation. Electric field of single point charge kq E = rˆ r2 Electric potential of single point charge b V E dl a kq Er ˆ r 2 b kq V rˆ dl 2 a r Electric potential of single point charge b V E dl a kq Er ˆ r 2 b kq V rˆ dl 2 a r kq kq VVV ba rrba kq V const. r 0 by convention Potential for Multiple Charges EEEE1 2 3 b V E dl a b b b E dl E dl E dl 1 2 3 a a a VVVV 1 2 3 Charges Q and q (Q ≠ q), separated by a distance d, produce a potential VP = 0 at point P. This means that 1) no force is acting on a test charge placed at point P. 2) Q and q must have the same sign. 3) the electric field must be zero at point P. 4) the net work in bringing Q to distance d from q is zero. -
Chapter 6 Inductance, Capacitance, and Mutual Inductance
Chapter 6 Inductance, Capacitance, and Mutual Inductance 6.1 The inductor 6.2 The capacitor 6.3 Series-parallel combinations of inductance and capacitance 6.4 Mutual inductance 6.5 Closer look at mutual inductance 1 Overview In addition to voltage sources, current sources, resistors, here we will discuss the remaining 2 types of basic elements: inductors, capacitors. Inductors and capacitors cannot generate nor dissipate but store energy. Their current-voltage (i-v) relations involve with integral and derivative of time, thus more complicated than resistors. 2 Key points di Why the i-v relation of an inductor isv L ? dt dv Why the i-v relation of a capacitor isi C ? dt Why the energies stored in an inductor and a capacitor are: 1 1 w Li, 2 , 2 Cv respectively? 2 2 3 Section 6.1 The Inductor 1. Physics 2. i-v relation and behaviors 3. Power and energy 4 Fundamentals An inductor of inductance L is symbolized by a solenoidal coil. Typical inductance L ranges from 10 H to 10 mH. The i-v relation of an inductor (under the passive sign convention) is: di v L , dt 5 Physics of self-inductance (1) Consider an N1 -turn coil C1 carrying current I1 . The resulting magnetic fieldB 1() r 1 N 1(Biot- I will pass through Savart law) C1 itself, causing a flux linkage 1 , where B1() r 1 N 1 , 1 B1 r1() d s1 P 1, 1 N I S 1 P1 is the permeance. 2 1 PNI 1 11. 6 Physics of self-inductance (2) The ratio of flux linkage to the driving current is defined as the self inductance of the loop: 1 2 L1NP 1 1, I1 which describes how easy a coil current can introduce magnetic flux over the coil itself. -
Chapter 2: Circuit Elements
Chapter 2: Circuit Elements Objectives o Understand concept of basic circuit elements . Resistor, voltage source, current source, capacitor, inductor o Learn to apply KVL, KCL, Ohm’s Law . Sign conventions Homework/Quiz/Exam Prep o When do we have enough equations? o Math requirements . Simultaneous linear algebraic equations Presentation o Ideal Basic Circuit Elements . Sources: Dependent and Independent . R, L, C o Resistors . Ohm’s Law . Power o Flashlight Circuit . KVL, KCL, Ohm . KVL shortcut o Special Cases . Short circuit; Open circuit . What happens to resistors that are shorted/opened? Activity: worksheet on KVL, KCL, Ohm Activity: sample problems Chapter 2: Circuit Elements There are five Ideal Basic Circuit Elements. We listed these in the previous chapter; we discuss them further here. The Ideal Basic Circuit Elements are as follows. Voltage source Current source Resistor Capacitor Inductor These circuit elements are used to model electrical systems, as we discussed in Chapter 1. They are available in the laboratory, but the ones in the lab are not “ideal”; they are “real”. When we draw circuit models on the board or in quizzes and exams, we assume that ideal elements are intended, unless otherwise stated. To solve circuits involving capacitors and inductors, we require differential equations. Therefore we will postpone these circuit elements until later in the course and deal for the moment with sources and resistors only. 2.1 Sources Source: a device capable of conversion between non-electrical energy and electrical energy. Examples… Generator: mechanical electrical Motor: electrical mechanical Important: energy and power can be either delivered or absorbed, depending on the circuit element and how it is connected into the circuit. -
Electrochemistry a Chem1 Supplement Text Stephen K
Electrochemistry a Chem1 Supplement Text Stephen K. Lower Simon Fraser University Contents 1 Chemistry and electricity 2 Electroneutrality .............................. 3 Potential dierences at interfaces ..................... 4 2 Electrochemical cells 5 Transport of charge within the cell .................... 7 Cell description conventions ........................ 8 Electrodes and electrode reactions .................... 8 3 Standard half-cell potentials 10 Reference electrodes ............................ 12 Prediction of cell potentials ........................ 13 Cell potentials and the electromotive series ............... 14 Cell potentials and free energy ...................... 15 The fall of the electron ........................... 17 Latimer diagrams .............................. 20 4 The Nernst equation 21 Concentration cells ............................. 23 Analytical applications of the Nernst equation .............. 23 Determination of solubility products ................ 23 Potentiometric titrations ....................... 24 Measurement of pH .......................... 24 Membrane potentials ............................ 26 5 Batteries and fuel cells 29 The fuel cell ................................. 29 1 CHEMISTRY AND ELECTRICITY 2 6 Electrochemical Corrosion 31 Control of corrosion ............................ 34 7 Electrolytic cells 34 Electrolysis involving water ........................ 35 Faraday’s laws of electrolysis ....................... 36 Industrial electrolytic processes ...................... 37 The chloralkali -
What Is Electricity
ELECTRICITY - A Secondary Energy Source A Secondary Source The Science of Electricity How Electricity is Generated/Made The Transformer - Moving Electricity Measuring Electricity energy calculator links page recent statistics A SECONDARY SOURCE Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable. Electricity is a basic part of nature and it is one of our most widely used forms of energy. Many cities and towns were built alongside waterfalls (a primary source of mechanical energy) that turned water wheels to perform work. Before electricity generation began over 100 years ago, houses were lit with kerosene lamps, food was cooled in iceboxes, and rooms were warmed by wood-burning or coal-burning stoves. Beginning with Benjamin Franklin's experiment with a kite one stormy night in Philadelphia, the principles of electricity gradually became understood. Thomas Edison helped change everyone's life -- he perfected his invention -- the electric light bulb. Prior to 1879, direct current (DC) electricity had been used in arc lights for outdoor lighting. In the late-1800s, Nikola Tesla pioneered the generation, transmission, and use of alternating current (AC) electricity, which can be transmitted over much greater distances than direct current. Tesla's inventions used electricity to bring indoor lighting to our homes and to power industrial machines. -
Electric Potential Equipotentials and Energy
Electric Potential Equipotentials and Energy Phys 122 Lecture 8 G. Rybka Your Thoughts • Nervousness about the midterm I would like to have a final review of all the concepts that we should know for the midterm. I'm having a lot of trouble with the homework and do not think those questions are very similar to what we do in class, so if that's what the midterm is like I think we need to do more mathematical examples in class. • Confusion about Potential I am really lost on all of this to be honest I'm having trouble understanding what Electric Potential actually is conceptually. • Some like the material! I love potential energy. I think it is These are yummy. fascinating. The world is amazing and physics is everything. A few answers Why does this even matter? Please go over in detail, it kinda didn't resonate with practical value. This is the first pre-lecture that really confused me. What was the deal with the hill thing? don't feel confident in my understanding of the relationship of E and V. Particularly calculating these. If we go into gradients of V, I will not be a happy camper... The Big Idea Electric potential ENERGY of charge q in an electric field: b ! ! b ! ! ΔU = −W = − F ⋅ dl = − qE ⋅ dl a→b a→b ∫ ∫ a a New quantity: Electric potential (property of the space) is the Potential ENERGY per unit of charge ΔU −W b ! ! ΔV ≡ a→b = a→b = − E ⋅ dl a→b ∫ q q a If we know E, we can get V The CheckPoint had an “easy” E field Suppose the electric field is zero in a certain region of space. -
A Visual Tutorial for Schematics
A Tutorial for Schematics - the PSpice Schematic Capture Utility * Schematics Netlist X_U1 $N_0002 $N_0003 $N_0004 $N_0005 $N_0001 UA741 V_VCC $N_0004 0 dc 10 V_VEE $N_0005 0 dc -10 V_Vin $N_0006 0 dc 0 ac 1 R_R1 $N_0006 $N_0007 2732 R_R2 $N_0007 $N_0002 2732 R_R4 $N_0003 $N_0001 1.52k R_R3 0 $N_0003 10k C_C1 $N_0007 $N_0001 1n C_C2 0 $N_0002 1n X_U2 $N_0008 $N_0009 $N_0004 $N_0005 vout UA741 R_R1B $N_0001 $N_0010 2732 R_R2B $N_0010 $N_0008 2732 Outline/Contents PART I. PSPICE FUNDAMENTALS I. Introductory Remarks ……………………………………………………………… 3 A. Spice, PSpice and Schematics B. Font Conventions C. The Passive Sign Convention and PSpice II. What is Schematics and what can it do for you? ………………………………….... 4 III. Units and Unit Prefixes ………………………………………………………..…… 4 PART II. CONSTRUCTING AND SIMULATING A DC CIRCUIT I. Drawing Circuit Diagrams with Schematics …………………………………….….. 5 A. Getting Parts …………………………………………………………………….. 6 B. Changing a Part’s Name and Attributes ………………………………………… 7 C. Arranging Parts and Pin Numbers ………………………………………………. 8 D. Wiring Parts ……………………………………………………………………... 8 E. The Analog Ground ………………………………………………………………9 F. Saving Schematics ………………………………………………………………. 9 II. Getting Results ………………………....………………………………………..….. 10 A. The Netlist, Arrgh! B. Naming Nodes …………………………………………………………………. 10 C. Displaying Results on the Schematic ………………………………………….. 11 D. Printing your Drawing …………………………………………………………. 11 III. Running PSpice from Schematics and Choosing an Analysis Type ……………….. 13 A. Obtaining a Bias Point Detail ……………………………………………… 14 B. Obtaining a dc Sweep ……………..………………….…………………… 15 IV. Running and Using PROBE ……………………………………………………….. 16 A. Adding Traces B. Using Markers C. Other PROBE Features - Label, Cursor, Copying and Saving ……………….. 19 V. Printing your Drawing. ……………………………..……………………………… 12 VI. Your First Schematic ………………………………………………………………. 20 PART III. CONSTRUCTING AND SIMULATING AN AC CIRCUIT I. Obtaining an ac Analysis and making Bode Plots …………………………………. -
Equipotential Surfaces: the Electric Potential Is Constant on the Surface • Equipotential Surfaces Are Perpendicular to Electric Field Lines
Physics 2102 Jonathan Dowling PPhhyyssicicss 22110022 LLeeccttuurree 55 EElleeccttrriicc PPootteennttiiaall II EElleeccttrriicc ppootteennttiiaall eenneerrggyy Electric potential energy of a system is equal to minus the work done by electrostatic forces when building the system (assuming charges were initially infinitely separated) U= − W∞ The change in potential energy between an initial and final configuration is equal to minus the work done by the electrostatic forces: ΔU= Uf − Ui= − W +Q • What is the potential energy of a single charge? +Q –Q • What is the potential energy of a dipole? a • A proton moves from point i to point f in a uniform electric field, as shown. • Does the electric field do positive or negative work on the proton? • Does the electric potential energy of the proton increase or decrease? EElleeccttrriicc ppootteennttiiaall Electric potential difference between two points = work per unit charge needed to move a charge between the two points: ΔV = Vf–Vi = −W/q = ΔU/q r dW = F • dsr r r dW = q0 E • ds f f r W = dW = q E • dsr # # 0 i i f W r !V = V "V = " = " E • dsr f i # q0 i EElleeccttrriicc ppootteennttiiaall eenneerrggyy,, eelleeccttrriicc ppootteennttiiaall Units : [U] = [W]=Joules; [V]=[W/q] = Joules/C= Nm/C= Volts [E]= N/C = Vm 1eV = work needed to move an electron through a potential difference of 1V: W=qΔV = e x 1V = 1.60 10–19 C x 1J/C = 1.60 10–19 J EEqquuipipootteennttiaiall ssuurrffaacceess f W r !V = V "V = " = " E • dsr f i q # Given a charged system, we can: 0 i • draw electric field lines: the electric field is tangent to the field lines • draw equipotential surfaces: the electric potential is constant on the surface • Equipotential surfaces are perpendicular to electric field lines. -
Electric Potential Equipotentials and Energy Today: Mini-Quiz + Hints for HWK
Electric Potential Equipotentials and Energy Today: Mini-quiz + hints for HWK U = qV Should lightening rods have a small or large radius of curvature ? V is proportional to 1/R. If you want a high voltage to pass through the rod then use a small radius of curvature. Air is normally an insulator, however for large E fields (E>3 x 10 6 V/m) it starts conducting. Empire State Building, NYC Electrical Potential Review: Wa → b = work done by force in going from a to b along path. b b r r b r r Wa →b = F • ld = qE • ld ∫a ∫a F b r r θ ∆U = Ub −U a = −Wa →b = −∫ qE • ld a a dl U = potential energy b r r ∆U Ub −U a Wa →b ∆V = Vb −Va = = = − = −∫ E • ld q q q a • Potential difference is minus the work done per unit charge by the electric field as the charge moves from a to b. • Only changes in V are important; can choose the zero at any point. Let Va = 0 at a = infinity and Vb → V, then: r r r V = electric potential V = −∫ E • ld ∞ allows us to calculate V everywhere if we know E Potential from charged spherical shell • E-field (from Gauss' Law) V q q • : 4πεπεπε 000 R 4πεπεπε 000 r r < R Er = 0 1 q • r >R: E = R r r 4πε 2 0r R • Potential R • r > R: r === r r r r 1 Qq V r( ) === −−− ∫∫∫ E ••• ld === −−− ∫∫∫ E r ( dr ) === r === ∞∞∞ ∞∞∞ 4πεπεπε 0 r • r < R: r===r r r r aR r 1 Qq V )r( === −−− ∫∫∫ E••• ld === −−−∫∫∫ Er dr( )=== −−−∫∫∫ Er dr( )−−−∫∫∫ Er dr( ) === +++0 4πεπεπε 0 aR r===∞∞∞ ∞∞∞ ∞∞∞ Ra ELECTRIC POTENTIAL for Charged Sphere (Y&F, ex.23.8) Suppose we have a charged q metal sphere with charge q.