Electricity and Magnetism

Information about Electricity and Magnetism

Published on April 29, 2009

Author: ankush85

Source: authorstream.com

Content

Electricity and Magnetism : Electricity and Magnetism Electric forces hold atoms and molecules together. Electricity controls our thinking, feeling, muscles and metabolic processes. Electricity and magnetism underpin much of our current technology (e.g. computers). Electricity and magnetism are linked on a fundamental level. Electric Charges : Electric Charges Evidence for electric charges is everywhere, e.g. static electricity. lightning. Objects may become charged by contact and frictional forces. Benjamin Franklin (1700’s) discovered that there are two types of charges: positive charge. negative charge. Franklin also discovered that like charges repel and unlike charges attract one another. Electric charge is quantized (Millikan) conserved (Franklin) Electric Charges in Atoms : Electric Charges in Atoms Atoms consist of a nucleus containing positively charged protons. The nucleus of an atom is surrounded by an equal number of negatively charged electrons. The net charge on an atom is zero. An atom may gain or lose electrons, becoming an ion with a net negative or positive charge. Polar molecules have zero net charge but their charges are unevenly distributed in space (e.g. water). Nuclear diameter ~ 10-15 m (femtometer) Atomic diameter ~ 10-9 m (nanometer) Classes of Materials : Classes of Materials CONDUCTORS are materials in which charges may move freely (e.g. copper). INSULATORS are materials in which charges cannot move freely (e.g. glass). SEMICONDUCTORS are materials in which charges may move under some conditions (e.g. silicon). Charges and the Earth : Charges and the Earth The earth acts as a near-infinite source or sink of charges, and therefore its net charge cannot easily be changed. Any conductor in contact with the earth is said to be GROUNDED and cannot receive a net charge. (principle of lightning rod) Induced Charge : Induced Charge Charged objects brought close to a conductor may cause charge to redistribute (polarize the conductor). If a polarized conductor is momentarily grounded, charge will be transferred to/from the earth, and it may be left with a net charge (by INDUCTION). Objects may be charged by conduction (requires contact with another charged object. induction (requires no contact with another charged object). Electric Force and Coulomb’s Law : Electric Force and Coulomb’s Law If two point charges q1 and q2 are separated by a distance r, the magnitude of the electric force Fe between them is: where k = 8.99 x 10 9 N? m2/C2 is the Coulomb constant, q1 and q2 are in Coulombs (C), r is in meters (m) and Fe is in Newtons (N). Quantum of Electric Charge : Quantum of Electric Charge Electric charge is quantized. The smallest possible unit is the charge on one electron or one proton: ?e?= 1.602 x 10-19 Coulombs No smaller charge has ever been detected in an experiment. Electric Force Vector : Electric Force Vector The force on a point charge q1 exerted by another point charge q2 separated by a distance r21 is: Principle of Superposition : Principle of Superposition For a system of N charges q1, q2, q3, …, qN, the resultant force F1 on q1 exerted by charges q2, q3, …, qN is: Each charge may be considered to exert a force on q1 that is independent of the other charges present. Field Forces and Electric Field : Field Forces and Electric Field Field forces act through space even if there is no contact (e.g. gravitational force). The ELECTRIC FIELD E is defined in terms of the electric force that would act on a positive test charge q0 : Electric Field : Electric Field The electric force on a positive test charge q0 at a distance r from a single charge q: The electric field at a distance r from a single charge q: Electric Field due to a Group of Charges: : Electric Field due to a Group of Charges: Example Problem : Example Problem Four point charges are at the corners of a square of side a as shown. Determine the magnitude and direction of the electric field at the location of q. What is the resultant force on q? 2q q 4q 3q a a a a Electric Field from Continuous Charge Distributions : Electric Field from Continuous Charge Distributions If a total charge Q is distributed continuously, it may be sub-divided into elemental charges dQ, each producing an electric field dE: e0 = permittivity of free space Uniform Charge Distributions : Uniform Charge Distributions Volume Charge Density: ?=Q/V Surface Charge Density: s=Q/A Linear Charge Density: ?=Q/l Example: A continuous line of charge lies along the x-axis, extending from x=x0 to positive infinity. The line carries a uniform linear charge density ?0. What are the magnitude and direction of the electric field at the origin? Example Problem: Electric Field due to a Power Line : Example Problem: Electric Field due to a Power Line A power line is suspended a constant distance yo above the ground, and carries a uniform linear charge density ?o. Assume that the wire is infinitely long and that the ground is a flat plane. What are the magnitude and direction of the electric field on the ground immediately below the power line? Electric Field Lines : Electric Field Lines Electric Field Lines: describe the direction of the electric field at any point The density of field lines is proportional to the magnitude of the electric field. The directions of arrows indicate the direction of the force on a positive test charge. Rules: Lines begin on + charge and end on – charge Number of lines approaching or leaving a charge is proportional to the magnitude of the charge. Electric field lines may never cross. Electric Field Lines: Conventions : Electric Field Lines: Conventions Positive Point Charge Negative Point Charge Electric Field lines : Electric Field lines

Related presentations


Other presentations created by ankush85

Nanotechnology
03. 04. 2009
0 views

Nanotechnology

Human Resource Management System
06. 03. 2009
0 views

Human Resource Management System

Nanotechnology
27. 03. 2009
0 views

Nanotechnology

INTRODUCTION TO NANOTECHNOLOGY
20. 11. 2009
0 views

INTRODUCTION TO NANOTECHNOLOGY

Nanotechnology in Sports
22. 11. 2009
0 views

Nanotechnology in Sports

Computer Architecture
14. 07. 2009
0 views

Computer Architecture

HR
18. 03. 2009
0 views

HR

Hospital Management System
08. 04. 2009
0 views

Hospital Management System

Welcome to Visual Basic
06. 03. 2009
0 views

Welcome to Visual Basic

HTML
20. 04. 2009
0 views

HTML

Computer Languages
03. 06. 2013
0 views

Computer Languages

Taking Care of Computer
03. 06. 2013
0 views

Taking Care of Computer

Understanding Camera
16. 10. 2012
0 views

Understanding Camera

Photography Technical Terms
25. 09. 2012
0 views

Photography Technical Terms

Basics of Photography
25. 09. 2012
0 views

Basics of Photography

AIR MUSCLES
03. 01. 2012
0 views

AIR MUSCLES

Molecular Nanotechnology
24. 11. 2009
0 views

Molecular Nanotechnology

Nanotech Innovation
22. 11. 2009
0 views

Nanotech Innovation

FINANCIAL  MARKET
16. 05. 2009
0 views

FINANCIAL MARKET

Operating System
19. 04. 2009
0 views

Operating System

Management Control
10. 07. 2009
0 views

Management Control

Accounting Principles
01. 07. 2009
0 views

Accounting Principles

Balance Sheet
21. 07. 2009
0 views

Balance Sheet

Balance Sheet Auditing
01. 07. 2009
0 views

Balance Sheet Auditing

BRANCH AND BOUND
05. 03. 2009
0 views

BRANCH AND BOUND

THE  THREE  BRANCHES  OF GOVERNMENT
13. 06. 2009
0 views

THE THREE BRANCHES OF GOVERNMENT

Structure of Atom
11. 05. 2009
0 views

Structure of Atom

Compression Techniques
05. 03. 2009
0 views

Compression Techniques

DYNAMIC PROGRAMMING
06. 03. 2009
0 views

DYNAMIC PROGRAMMING

Quantum Mechanics
25. 08. 2009
0 views

Quantum Mechanics

Marketing Plan
19. 06. 2009
0 views

Marketing Plan

Book Keeping
24. 06. 2009
0 views

Book Keeping

DFDS
02. 10. 2008
0 views

DFDS

Semiconductors
25. 04. 2009
0 views

Semiconductors

Organic  Chemistry
28. 04. 2009
0 views

Organic Chemistry

Atoms Molecules and Ions
17. 06. 2009
0 views

Atoms Molecules and Ions

Covalent Bond
25. 04. 2009
0 views

Covalent Bond

Cost Accounting Standards
25. 06. 2009
0 views

Cost Accounting Standards

Crisis Management
19. 06. 2009
0 views

Crisis Management

Marketing
18. 03. 2009
0 views

Marketing

Business Strategy
27. 04. 2009
0 views

Business Strategy

Time Management
23. 03. 2009
0 views

Time Management

Networking Protocols
23. 05. 2009
0 views

Networking Protocols

Network Layer
23. 05. 2009
0 views

Network Layer

Final Accounts
24. 06. 2009
0 views

Final Accounts

ARTIFICIAL  INTELLIGENCE
03. 04. 2009
0 views

ARTIFICIAL INTELLIGENCE

Play with C
08. 04. 2009
0 views

Play with C

Software Development Cycle
23. 03. 2009
0 views

Software Development Cycle

THE GREEDY METHOD
06. 03. 2009
0 views

THE GREEDY METHOD

JOB SEQUENCING
06. 03. 2009
0 views

JOB SEQUENCING

Optical Fiber
24. 05. 2009
0 views

Optical Fiber

Quality Assurance
06. 03. 2009
0 views

Quality Assurance

Object-oriented Design
11. 04. 2009
0 views

Object-oriented Design

A.R. Rahman
08. 03. 2009
0 views

A.R. Rahman

Hollywood Female Celebrities
13. 03. 2009
0 views

Hollywood Female Celebrities

Flow nets
04. 09. 2009
0 views

Flow nets

Energy and Nanotechnology
22. 11. 2009
0 views

Energy and Nanotechnology

LOGIC  DESIGN
06. 03. 2009
0 views

LOGIC DESIGN

VB-IDE
06. 03. 2009
0 views

VB-IDE

DLF IPL FINAL
25. 05. 2009
0 views

DLF IPL FINAL

MINIMUM SPANNING TREES
06. 03. 2009
0 views

MINIMUM SPANNING TREES

CPU Scheduling
05. 03. 2009
0 views

CPU Scheduling

Virtual Memory
05. 03. 2009
0 views

Virtual Memory

POK
09. 05. 2009
0 views

POK

2D Transformations
05. 03. 2009
0 views

2D Transformations

Greedy Algorithms
05. 03. 2009
0 views

Greedy Algorithms

BACKTRACKING
05. 03. 2009
0 views

BACKTRACKING

DIVIDE And CONQUER
06. 03. 2009
0 views

DIVIDE And CONQUER

ELEMENTARY DATA STRUCTURES
06. 03. 2009
0 views

ELEMENTARY DATA STRUCTURES

JPEG Compression
06. 03. 2009
0 views

JPEG Compression

Mpeg-compression
06. 03. 2009
0 views

Mpeg-compression

NP - HARD
06. 03. 2009
0 views

NP - HARD

TRAVELLING SALESPERSON PROBLEM
06. 03. 2009
0 views

TRAVELLING SALESPERSON PROBLEM

VBA Introduction
06. 03. 2009
0 views

VBA Introduction

Introduction to Java
09. 03. 2009
0 views

Introduction to Java

Java  Basics
09. 03. 2009
0 views

Java Basics

Heuristic Search
13. 03. 2009
0 views

Heuristic Search

HSM
19. 03. 2009
0 views

HSM

Tata's  Nano  Car
25. 03. 2009
0 views

Tata's Nano Car

Air Cranes
08. 04. 2009
0 views

Air Cranes

Newborn Care
10. 04. 2009
0 views

Newborn Care

Photosynthesis Process
10. 04. 2009
0 views

Photosynthesis Process

ActionScript
13. 04. 2009
0 views

ActionScript

Xml
15. 04. 2009
0 views

Xml

Snakes mis use
17. 04. 2009
0 views

Snakes mis use

Php Web Development
21. 04. 2009
0 views

Php Web Development

Cricket Intro
21. 04. 2009
0 views

Cricket Intro

Cricket Umpiring and Rules
21. 04. 2009
0 views

Cricket Umpiring and Rules

Arm and Forearm
23. 04. 2009
0 views

Arm and Forearm

Elements Ions Isotopes
25. 04. 2009
0 views

Elements Ions Isotopes

Chemical Bond
25. 04. 2009
0 views

Chemical Bond

Discovering Newtons Laws
29. 04. 2009
0 views

Discovering Newtons Laws

FreeFall
29. 04. 2009
0 views

FreeFall

Digital photography
26. 04. 2009
0 views

Digital photography

Health Effects of Alcohol
26. 04. 2009
0 views

Health Effects of Alcohol

Poetry Terminology
27. 04. 2009
0 views

Poetry Terminology

Indian Force
05. 05. 2009
0 views

Indian Force

Machine Intelligence
14. 05. 2009
0 views

Machine Intelligence

Data Link Layer
16. 05. 2009
0 views

Data Link Layer

Database Development Cycle
15. 05. 2009
0 views

Database Development Cycle

Queue
15. 05. 2009
0 views

Queue

Presentaion Skills
23. 04. 2009
0 views

Presentaion Skills

Network Layers
23. 05. 2009
0 views

Network Layers

Narmada Dam, India
23. 05. 2009
0 views

Narmada Dam, India

User Datagram Protocol
24. 05. 2009
0 views

User Datagram Protocol

Linear Momentum
28. 05. 2009
0 views

Linear Momentum

Stack and Queue
04. 06. 2009
0 views

Stack and Queue

Information Management
19. 06. 2009
0 views

Information Management

Role of Senior Management
19. 06. 2009
0 views

Role of Senior Management

Wake Up India
07. 06. 2009
0 views

Wake Up India

Adobe Flex 3.0
13. 06. 2009
0 views

Adobe Flex 3.0

Adobe Flex Presentation
13. 06. 2009
0 views

Adobe Flex Presentation

Introduction to Adobe Flex
13. 06. 2009
0 views

Introduction to Adobe Flex

Adobe Flash Media Server
13. 06. 2009
0 views

Adobe Flash Media Server

Dreamweaver
13. 06. 2009
0 views

Dreamweaver

Adobe Flash
13. 06. 2009
0 views

Adobe Flash

Flash CS4 Professional
13. 06. 2009
0 views

Flash CS4 Professional

Adobe Flash Lite
13. 06. 2009
0 views

Adobe Flash Lite

Digital Camera
13. 06. 2009
0 views

Digital Camera

Mozilla_Firefox
15. 06. 2009
0 views

Mozilla_Firefox

Managerial Accounting
27. 06. 2009
0 views

Managerial Accounting

Accounting  Information  System
01. 07. 2009
0 views

Accounting Information System

RETAILING AND MARKETING
06. 07. 2009
0 views

RETAILING AND MARKETING

ACCOUNTING IN BUSINESS
05. 07. 2009
0 views

ACCOUNTING IN BUSINESS

STRATEGIC RETAIL MANAGEMENT
05. 07. 2009
0 views

STRATEGIC RETAIL MANAGEMENT

Reiki
01. 08. 2009
0 views

Reiki

Using Buttons in PowerPoint
26. 04. 2009
0 views

Using Buttons in PowerPoint

Nanotechnology  for  Students
21. 08. 2009
0 views

Nanotechnology for Students

NANOSCIENCE
25. 08. 2009
0 views

NANOSCIENCE

Fundamentals of Nanoscience
27. 08. 2009
0 views

Fundamentals of Nanoscience

Nanoscience in Nature
27. 08. 2009
0 views

Nanoscience in Nature

Applied Mechanics
04. 09. 2009
0 views

Applied Mechanics

Accounts Payable Training
27. 06. 2009
0 views

Accounts Payable Training