* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Fundamentals of Electricity
Survey
Document related concepts
Potential energy wikipedia , lookup
Introduction to gauge theory wikipedia , lookup
Aharonov–Bohm effect wikipedia , lookup
Maxwell's equations wikipedia , lookup
History of electromagnetic theory wikipedia , lookup
Anti-gravity wikipedia , lookup
Field (physics) wikipedia , lookup
Nuclear physics wikipedia , lookup
Atomic nucleus wikipedia , lookup
Electromagnetism wikipedia , lookup
Lorentz force wikipedia , lookup
Electrical resistivity and conductivity wikipedia , lookup
Electrical resistance and conductance wikipedia , lookup
Transcript
Charges Electrons e- P+ n nucleus Source of Electrons(Force) Matter : Weight - Space Solid Liquid Gas Plasma Atoms valence shell eP n nucleus Atoms Atomic Number – Number of Protons Atomic Weight – Number of Protons plus Neutrons Number of Protons EQUALS Electrons in a neutral atom Ionization The process where an atom gains or loses an electron. + Na Cl Na – Positive Ion Cl – Negative Ion Charges (q) Like Charges (++ q- q- q+ q+ - -) Charges (q) Un-Like Charges (+ -) q+ q- Coulomb’s Law Coulomb (C) The quantity of charge on an abject. 1C = 6.25 x 1018 e- Coulomb’s Law q- Coulomb’s Law q1 q2 What does the force depend on? Coulomb’s Law q1 d q2 1.The charge on q1 and q2 . 2.The distance (d). d 2 d q- Mathematical Model for Coulomb’s Law Force (F) q1 d q2 F ∞ q1q2 F ∞ 1/d2 q1 d q2 K q1q 2 F= 2 d K = 9.0 X 9 10 2 2 N·m /C q1 d=3cm q2 -6 +6x10 C q1= +6μC = -6 q2= +3μC = +6x10 C -2 d = 3cm = 3x10 m K = 9.0 X 9 10 2 2 N·m /C What is the force on q2? K q1q2 F= 2 d 9X109N·m2/C2(6X10-6C)(6X10-6C) 2 -2 (3X10 m) F= q1 2 1.8X10 N q2 Electric Fields Think of gravity or gravitational field to understand electric fields. Electric Fields vs g Gravity Electric ++++++++++ Fields neutral neutral ---------- E Electric ++++++++++ Fields + ---------- E + Electric ++++++++++ Fields ---------- E - Electric Fields A force field due to electric charges. A force on a charge due to another chage. E Electric Field: Point Charge r q kq E = r2 Force on a charge ‘q’ in an Electric Field Q q F E=q F E=q E= Newton Coulomb E= N C Energy and Work Energy and Work + - It takes work to move the “-” charge. Electric Potential (Energy) Voltage + q’ Work on q’ Joule ΔV = == volt q’ Coulomb Electric Potential (Energy) Voltage + VA q’ ΔV = VB - VA VB “Potential Difference” Voltage Electric Potential (Energy) Voltage Fd ΔV = q F E= q Eqd ΔV = q Electric Potential (Energy) Voltage ΔV = Ed Example Two parallel plates are given opposite charges. A voltmeter measures the electric potental differnece to be 60V. The plates are 3.ocm apart. What is the magnitude of the electric field between them. ---------- ΔV d E ++++++++++ ΔV=60.0V D=0.030m ΔV = Ed ΔV =E d 60V =E 0.03m 2000J/(m·C)= E 2000 N/C = E Current Flow of charge! Charge - Coulomb(C) 6.24 X 1018 electrons e e e eee e e e e ee e ee e Leyden Jar Conductors Leyden Jar + + + + + + -++-+ -+ +---+ --- Capacitor A capacitor is a passive electronic component that stores energy in the form of an electrostatic field. Capacitor Metal Plates Insulating Material Dielectric Capacitor + e e - e e e ee ee e e e e e e eeee e e e Capacitor - - -- - - -++++ ++++ Zinc - Copper Current e e e eee e e e e ee e ee e Number of electrons passing a point in a second. Current Symbol - I Unit – Ampere (Amps) Amperes - A Force e e e eee e e e e ee e ee e Voltage Potential Difference Electromotive Force (EMF) Voltage Symbol - V Unit – Volt Volt - V Resistance Opposition to Current Flow High Resistance Insulator Resistance Opposition to Current Flow Low Resistance Conductor Resistance Opposition to Current Flow High and Low Resistance SemiConductor Resistance Symbol - R Unit – Ohm Ohm - Ω Putting it all Together Load Source Path Homework: 1-1 Worksheet Due: 9/9/02 Test: 9/9/02