GEORG OHM - Ω Physicist and Mathematician

Total Page:16

File Type:pdf, Size:1020Kb

GEORG OHM - Ω Physicist and Mathematician GEORG OHM - Ω Physicist and Mathematician The start Georg Simon Ohm was born on 16th of March 1789 in Erlangen in Germany and died on 6th of July 1854 in Munich, Germany. He was born into a Protestant family and was the son of Johann Wolfgang Ohm and Maria Elizabeth Beck. The family had seven children, but only three survived: Georg, his younger brother Martin and his sister Elizabeth Barbara. His mother died when Georg was only 10 years old. Education Georg and Martin were taught by their father who brought them to a high standard in mathematics, physics, chemistry and philosophy. Georg Simon attended Erlangen Gymnasium from age eleven to fifteen where he hardly received any scientific education. After the Gymnasium, he was sent to Switzerland as his father was concerned that his son was wasting his educational opportunity. In September 1806 Ohm accepted a position as a mathematics teacher in a school in Gottstadt. Ohm restarted his mathematical studies, left his teaching post in March 1809 and became a private tutor in Neuchâtel. For two years he carried out his duties as a tutor while he followed private studies of mathematics. Then in April 1811 he returned to the University of Erlangen. Teaching Ohm received his doctorate from the University of Erlangen on October 25, 1811. He immediately joined the faculty there as a lecturer in mathematics but left after three semesters because of unpromising prospects. He could not survive on his salary as a lecturer. He had a few more teaching jobs after that and unhappy with his job, Georg began writing an elementary textbook on geometry as a way to prove his abilities. Ohm sent his completed manuscript to King Wilhelm III of Prussia, who appreciated Ohm's book and offered him a position at the Jesuit Gymnasium of Cologne on 11 September 1817. This school had a reputation for good science education and Ohm was required to teach physics as well as mathematics. The school had a brilliantly equipped physics laboratory, which allowed Ohm to begin experimenting with physics. Being the son of a locksmith, Ohm had some practical experience with mechanical devices, which came in handy. Publishings “Die galvanische Kette, mathematisch bearbeitet” (The Galvanic Circuit Investigated Mathematically) was published in 1827. His employers did not appreciate his book and Ohm resigned from his position. He then made an application to, and was employed by, the Polytechnic School of Nuremberg and joined them in 1833. In 1852 he became a professor of experimental physics at the University of Munich. In 1849, Ohm published “Beiträge zur Molecular-Physik“, (in English: Molecular Physics). He had hoped to write a second and third volume "and if God gives me length of days for it, a fourth". However, on finding that an original discovery recorded in it was being anticipated by a Swedish scientist he did not publish it, stating: "The episode has given a fresh and deep sense for my mind to the saying 'Man proposes, and God disposes'. The project that gave the first impetus to my inquiry has been dissipated into mist, and a new one, undesigned by me, has been accomplished in its place." Ohm’s Law Ohm's law first appeared in his famous book “Die galvanische Kette, mathematisch bearbeitet”, in which he gave his complete theory of electricity. In this work, he stated his law for electromotive force acting between the extremities of any part of a circuit is the product of the strength of the current, and the resistance of that part of the circuit. A good mathematical background is needed to understand the rest of the work. While his work greatly influenced the theory and applications of current electricity, it was not warmly received at that time. Ohm presents his theory as one of contiguous action, a theory which opposed the concept of action at a distance. Ohm believed that the communication of electricity occurred between "contiguous particles" which is the term he himself used. Using equipment of his own creation, Ohm found that there is a direct proportionality between the potential difference (voltage) applied across a conductor and the resultant electric current. Look at the drawing and see if it makes sense to you that: If you increase the voltage in a circuit while the resistance is the same, you get more current. If you increase the resistance in a circuit while the voltage stays the same, you get less current. Ohm’s law is a way of describing the relationship between the voltage, resistance and current using math: V = RI V is the symbol for voltage I is the symbol for current. R is the symbol for resistance. He related to the strength of a current in a wire. Ohm found that electricity acts like water in a pipe and discovered that the current in a circuit is directly proportional to the electric pressure and inversely to the resistance of the conductors. It was adopted as the SI unit of resistance, the ohm (symbol Ω). Acoustic law Ohm's acoustic law, sometimes called the acoustic phase law or simply Ohm's law, states that a musical sound is perceived by the ear as a set of a numbers of constituent pure harmonic tones. It is well known to be not quite true. Recognition Although Ohm's work strongly influenced theory, at first it was received with hardly any enthusiasm. However, in the end his work was recognized by the Royal Society with its award of the Copley Medal in 1841. He became a foreign member of the Royal Society in 1842, and in 1845 he became a full member of the Bavarian Academy of Sciences and Humanities. Interesting facts Georg had no formal science training. He created his own equipment. Ohm’s theory on electricity was rejected at first. His discovery was ignored for years. He also wrote a textbook on Geometry. He has his own symbol Ω (the Greek letter Omega). Luke Moore / 10A .
Recommended publications
  • Laboratory Manual Physics 166, 167, 168, 169
    Laboratory Manual Physics 166, 167, 168, 169 Lab manual, part 2 For PHY 167 and 169 students Department of Physics and Astronomy HERBERT LEHMAN COLLEGE Spring 2018 TABLE OF CONTENTS Writing a laboratory report ............................................................................................................................... 1 Introduction: Measurement and uncertainty ................................................................................................. 3 Introduction: Units and conversions ............................................................................................................ 11 Experiment 1: Density .................................................................................................................................... 12 Experiment 2: Acceleration of a Freely Falling Object .............................................................................. 17 Experiment 3: Static Equilibrium .................................................................................................................. 22 Experiment 4: Newton’s Second Law .......................................................................................................... 27 Experiment 5: Conservation Laws in Collisions ......................................................................................... 33 Experiment 6: The Ballistic Pendulum ......................................................................................................... 41 Experiment 7: Rotational Equilibrium ........................................................................................................
    [Show full text]
  • Student Pages Part B 3C P2
    Fat: Who Says? Measuring Obesity by Bioelectrical Impedance Analysis Circuitous Adventures-Measuring Electrical Values Student Information Page 3C Part B Activity Introduction: Surge ahead and learn how to use a multimeter device to measure voltage, amps, and resistance. Resistance is futile! Activity Background: Whenever charged particles are taken from one object and given to another object, an imbalance of charge occurs. This imbalance of charge is called voltage (or potential difference). Voltage is measured in units called Volts (V), named after Alessandro Volta. An electric current is nothing more than the flow of electric charges from one location to another. The measure of how much flow is occurring at any given point is called the amperage and is measured in units called amps (A), named after André-Marie Ampère. Electric charges can only flow through certain materials, called conductors. Materials that resist the flow of current are called insulators. Materials offer resistance to the flow of current. This resistance is measured in units called ohms (Ω), named after its discovered Georg Ohm. Ohm’s law states that the amount of current (I) flowing through a conductor times the resistance (R) of the conductor is equal to voltage (V) of the source of power (i.e. batteries). This law is often expressed in the following form: V = I X R Note: V = voltage, I = current, and R = resistance Activity Materials: • 2 batteries • 1 battery holder • Several electrical wires (stripped) or with alligator clips • 1 buzzer • 1 switch • 1 Analog multimeter • 1 Copy Student Information Page • 1 Copy Student Data Page • Transparency of Figure 3 Part B LESSON 3 ® Positively Aging /M.O.R.E.
    [Show full text]
  • Energy Pioneers
    Providing energy education to students in the communities we serve. That’s our Promise to Michigan. Energy Pioneers The following pages will give an overview about famous people in history who studied energy and invented useful things we still use today. Read about these people then complete the matching activity on the last page. For more great energy resources visit: www.ConsumersEnergy.com/kids © 2015 Consumers Energy. All rights reserved. Providing energy education to students in the communities we serve. That’s our Promise to Michigan. Thomas Edison (1847) Information comes from the Department of Energy, including sourced pictures. Source: Wikimedia Commons (Public Domain) Born in 1847. Not a very good student. Created many inventions including the phonograph (similar to a record player), the light bulb, the first power plant and the first movie camera. One of his most famous quotes is, “Invention is one percent inspiration and ninety-nine percent perspiration.” For more great energy resources visit: www.ConsumersEnergy.com/kids © 2015 Consumers Energy. All rights reserved. Providing energy education to students in the communities we serve. That’s our Promise to Michigan. Marie Curie (1867) Information comes from the Department of Energy, including sourced pictures. Source: Nobel Foundation, Wikimedia Commons (Public Domain) Born in 1867. Learned to read at 4. There were no universities in her native Poland that accepted women, so she had to move to France to attend college. She, along with her husband, discovered the first radioactive element. In 1903, she was awarded the Nobel Prize in Physics for the discovery of radium. Marie Curie was the first woman to win a Nobel Prize in Physics.
    [Show full text]
  • Electrical Basics
    Electrical Basics Power & Ohm’s Law Group 1 • Work together to understand the informaon in your secon. • You will have 10 minutes to review the material and present it to the class. • With some applied force, electrons will move from a negatively charged atom to a positively charged atom. This flow of electrons between atoms is called current. • Current is represented by the symbol I 3 • When there is a lack of electrons at one end of a conductor and an abundance at the other end, current will flow through the conductor. This difference in “pressure” is referred to as voltage. • This “pressure” is sometimes referred to as “electromotive force” or EMF. • Voltage is represented by the symbol E 4 • Resistance is the opposition to the flow of electrons (aka “current”). • Every material offers some resistance. • Conductors offer very low resistance. • Insulators offer high resistance. • Resistance is represented by the Symbol R • Resistance is measured in Ohms Ω 5 • Current is measured by literally counting the number of electrons that pass a given point. • Current will be the same at any point of a wire. • The basic unit for counting electrons is the "coulomb“. (French physicist Charles Augustin de Coulomb in 1780’s) 6 • 1 coulomb = 6.24 x 1018 electrons = 6,240,000,000,000,000,000 = more than 6 billion billion electrons! If 1 coulomb of electrons go by each second, then we say that the current is 1 "ampere" or 1 amp (Named after André-Marie Ampère, 1826) 7 • Voltage is measured in volts. • A voltage of 1 volt means that 1 "Joule" of energy is being delivered for each coulomb of charge that flows through the circuit.
    [Show full text]
  • Electric Currents on the Body Current in Amperes Effect 0.001 Can Be Felt 0.005 Painful 0.010 Involuntary Muscle Contractions 0.015 Loss of Muscle Control
    Chapter 20 - Electric Circuits Physics Electric Current • Electric current is simply the flow of electric charges • Charge flows when there is an electric potential difference, or difference in potential (voltage), between the ends of a conductor. (Think of water pipes. Water can only flow if there a difference in gravitational potential energy between two points) • The flow of charge will continue until both ends reach a common electric potential. When there is no potential difference, there is no longer a flow of charge through the conductor • The unit of electric current is called the ampere (A) – named after André-Marie Ampère (1775–1836), French mathematician and physicist flow of charge - When the rate of flow of charge past any cross section of wire cross section is 1coulomb per second, the current is 1 ampere ( ) => Electric current(I) = rate of charge flow = ( ) amount of charge q I = [A]change in time t 풒 휟풕 Q1) A wire carries a current of 2.0A. How much charge passes by a point in 55 seconds? a) 110C b) 100C c) 90C d) 80C Q2) 175C of charge pass a point in a wire in 35s. What is the current in the wire? a) 1A b) 3A c) 5A d) 8A Q3) How much charge, in coulombs, passes through a cross section of a particular wire every second if the current in the wire is 3A? How many electrons would this charge be equivalent to? (q= ne, 1e = 1.6×10-19C) a) 5C, 3.2×1019e-/s b) 3C, 1.9×1019e-/s c) 5C, 1.9×1019e-/s d) 3C, 3.2×1019e-/s 1 Voltage Sources and Resistance i) Voltage Sources • Charges do not flow unless there is a potential difference(=Voltage) • A battery is one example of a voltage source.
    [Show full text]
  • The Short History of Science
    PHYSICS FOUNDATIONS SOCIETY THE FINNISH SOCIETY FOR NATURAL PHILOSOPHY PHYSICS FOUNDATIONS SOCIETY THE FINNISH SOCIETY FOR www.physicsfoundations.org NATURAL PHILOSOPHY www.lfs.fi Dr. Suntola’s “The Short History of Science” shows fascinating competence in its constructively critical in-depth exploration of the long path that the pioneers of metaphysics and empirical science have followed in building up our present understanding of physical reality. The book is made unique by the author’s perspective. He reflects the historical path to his Dynamic Universe theory that opens an unparalleled perspective to a deeper understanding of the harmony in nature – to click the pieces of the puzzle into their places. The book opens a unique possibility for the reader to make his own evaluation of the postulates behind our present understanding of reality. – Tarja Kallio-Tamminen, PhD, theoretical philosophy, MSc, high energy physics The book gives an exceptionally interesting perspective on the history of science and the development paths that have led to our scientific picture of physical reality. As a philosophical question, the reader may conclude how much the development has been directed by coincidences, and whether the picture of reality would have been different if another path had been chosen. – Heikki Sipilä, PhD, nuclear physics Would other routes have been chosen, if all modern experiments had been available to the early scientists? This is an excellent book for a guided scientific tour challenging the reader to an in-depth consideration of the choices made. – Ari Lehto, PhD, physics Tuomo Suntola, PhD in Electron Physics at Helsinki University of Technology (1971).
    [Show full text]
  • I. Electricity and Magnetism 2______3
    Electricity and Magnetism 2 By Henri RASOLONDRAMANITRA African Virtual university Université Virtuelle Africaine Universidade Virtual Africana African Virtual University NOTICE This document is published under the conditions of the Creative Commons http://en.wikipedia.org/wiki/Creative_Commons Attribution http://creativecommons.org/licenses/by/2.5/ License (abbreviated “cc-by”), Version 2.5. African Virtual University Table of conTenTs I. Electricity and Magnetism 2 __________________________________ 3 II. Prerequisite Course or knowledge _____________________________ 3 III. Time ____________________________________________________ 3 IV. Material __________________________________________________ 3 V. Module Rationale __________________________________________ 4 VI. Content __________________________________________________ 4 6.1 Overview ______________________________________________ 4 6.2 Outline________________________________________________ 5 6.3 Graphic Organizer _______________________________________ 5 VII. General Objective(s) ________________________________________ 6 VIII. Specific Learning Objectives __________________________________ 7 IX. Teaching and Learning Activities _______________________________ 9 X. Learning Activities _________________________________________ 20 XI. Key Concepts (Glossary) ___________________________________ 161 XII. Compulsory Readings _____________________________________ 164 XIII. Useful Links ____________________________________________ 167 XIV. Synthesis of the Module ___________________________________
    [Show full text]
  • A Guide to Low Resistance Measurement Contents
    Tried. Tested. Trusted. A Guide to Low Resistance Measurement Contents 02-03 Introduction 04-05 Applications 06 Resistance 06-09 Principles of Resistance Measurement 09-10 Methods of 4 Terminal Connections 10-19 Possible Measurement Errors 14-18 Choosing the Right Instrument 18-24 Application Examples 25-33 Useful Formulas and Charts 34 Find out more Tried. Tested. Trusted. With resistance measurement, precision is everything. This guide is what we know about achieving the highest quality measurements possible. The measurement of very large or very small cable characteristics, temperature coefficients quantities is always difficult, and resistance and various formulas to ensure you make the best measurement is no exception. Values above 1G possible choice when selecting your measuring Ω and values below 1 both present measurement instrument and measurement technique. Ω problems. We hope you will find this booklet a valuable Cropico is a world leader in low resistance addition to your toolkit. measurement; we produce a comprehensive range of low resistance ohmmeters and accessories which cover most measurement applications. This handbook gives an overview of low resistance measurement techniques, explains common causes of errors and how to avoid them. We have also included useful tables of wire and 2 Tried. Tested. Trusted. 3 Applications There are many reasons why the resistance of material is measured. Here are a few. Manufacturers of components thus avoiding the joint or contact from Resistors, inductors and chokes all have to becoming excessively hot, a poor cable joint or verify that their product meets the specified switch contact will soon fail due to this heating resistance tolerance, end of production line and effect.
    [Show full text]
  • Electrical Circuits
    Electrical Circuits This guide covers the following: ● What is a circuit? ● Circuit Symbols ● Series and Parallel Circuits ● Electrical Charge ● Voltage ● Current ● Current and Voltage in Series and Parallel circuits ● Resistance ● Ohm’s Law ● Electrical Power What is a Circuit? To power an electrical device we need a few things. 1. Power source (cell/battery/wall socket etc.) 2. An electrical circuit for the electricity to travel round. We know that electricity is the flow of electrons. If the electrons cannot move there is now electricity. For electrons to move much like a scalextric car they need a track or wire to move along. What is a Circuit? Electrical Circuits are the “tracks” that the electrons travel round. This “track” must start AND end with the power source. Spread around the “track” are the devices you want to power such as bulbs and motors etc. Circuit Symbols It can be difficult to draw a circuit that is easy to follow. Because of this a system has been developed to simplify the drawing of circuits. These are called Circuit Diagrams. Circuit Diagrams are easy to read and easy to draw! Circuit Diagrams replace components in the circuit with Circuit Symbols. Circuit Symbols Circuit Symbols Below are the most common circuit symbols. Types of Circuit Electrical Circuits come in three forms: 1. Series Circuits 2. Parallel Circuits 3. A combination of Series and Parallel Circuits These relate to how the components in the circuit are arranged. Series Circuits In Series Circuits the components are joined together in a chain. Like a daisy chain! Parallel Circuits In Parallel Circuits the components are joined so that each component has its own loop back to the battery.
    [Show full text]
  • What Is Ohm's Law?
    What is Ohm’s Law? Ohm’s Law is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit. To students of electronics, Ohm’s Law (E = IR) is as fundamentally important as Einstein’s Relativity equation (E = mc2) is to physicists. E = I x R When spelled out, it means voltage = current x resistance, or volts = amps x ohms, or V = A x Ω. Named for German physicist Georg Ohm (1789-1854), Ohm’s Law addresses the key quantities at work in circuits: Quantity Ohm’s Law Unit of measure Role in circuits In case you’re wondering: symbol (abbreviation) Voltage E Volt (V) Pressure that triggers E = electromotive force (old- electron flow school term) Current I Ampere, amp (A) Rate of electron flow I = intensity Resistance R Ohm (Ω) Flow inhibitor Ω = Greek letter omega If two of these values are known, technicians can reconfigure Ohm’s Law to calculate the third. Just modify the pyramid as follows: If you know voltage (E) and current (I) and want to know resistance (R), X-out the R in the pyramid and calculate the remaining equation (see the first, or far left, pyramid above). Note: Resistance cannot be measured in an operating circuit, so Ohm’s Law is especially useful when it needs to be calculated. Rather than shutting off the circuit to measure resistance, a technician can determine R using the above variation of Ohm’s Law. Now, if you know voltage (E) and resistance (R) and want to know current (I), X-out the I and calculate the remaining two symbols (see the middle pyramid above).
    [Show full text]
  • Electricity Is a Type of Energy That Can Build up in One Place Or Flow from One Place to Another
    Electricity is a type of energy that can build up in one place or flow from one place to another. A science that deals with the phenomena and laws of electricity Keen contagious excitement! Knowledge of electric eels dates back to 2750 BC. A Greek philosopher named Thales of Miletus made some observations about static electricity around 600 BC. Static electricity was generated by rubbing amber against fur in experiments and magic tricks. The word “Electricus” was first used in 1600, by an English scientist named William Gilbert. He took the word from the Greek word for amber: ήλεκτρον [elektron]. The word “Electricity” was first printed in 1646. 1752: Benjamin Franklin supposedly did the famous Key in a lightning storm experiment. We know for sure he did a lot of research. 1792: Luigi Galvani demonstrated that animals’ bodies run on electricity. 1800: Alessandro Volta's invented an early type of battery. 1820: Hans Christian Ørsted and André-Marie Ampère researched how magnets and electricity work together. 1821: Michael Faraday invented the electric motor. 1827: Georg Ohm mathematically analyzed the electrical circuit. Mid 1800’s and beyond: Nikola Tesla, Thomas Edison, George Westinghouse, Ernst Werner von Siemens, Alexander Graham Bell, Lord Kelvin, and others, all did very influential work in electricity. We have to look really close – at ATOMS! They have protons, neutrons, and electrons. Protons are POSITIVELY charged. Electrons are NEGATIVELY charged. Neutrons are NEUTRAL. When an electron gets removed from an atom, it’s still an atom of the same element, but the CHARGE is different! All atoms want to be neutral – they want to get that electron back! Opposites attract, so a positively charged atom will attract a negatively charged one.
    [Show full text]
  • The 100 Most Influential Scientists of All Time / Edited by Kara Rogers.—1St Ed
    Published in 2010 by Britannica Educational Publishing (a trademark of Encyclopædia Britannica, Inc.) in association with Rosen Educational Services, LLC 29 East 21st Street, New York, NY 10010. Copyright © 2010 Encyclopædia Britannica, Inc. Britannica, Encyclopædia Britannica, and the Thistle logo are registered trademarks of Encyclopædia Britannica, Inc. All rights reserved. Rosen Educational Services materials copyright © 2010 Rosen Educational Services, LLC. All rights reserved. Distributed exclusively by Rosen Educational Services. For a listing of additional Britannica Educational Publishing titles, call toll free (800) 237-9932. First Edition Britannica Educational Publishing Michael I. Levy: Executive Editor Marilyn L. Barton: Senior Coordinator, Production Control Steven Bosco: Director, Editorial Technologies Lisa S. Braucher: Senior Producer and Data Editor Yvette Charboneau: Senior Copy Editor Kathy Nakamura: Manager, Media Acquisition Kara Rogers: Senior Editor, Biomedical Sciences Rosen Educational Services Jeanne Nagle: Senior Editor Nelson Sá: Art Director Introduction by Kristi Lew Library of Congress Cataloging-in-Publication Data The 100 most influential scientists of all time / edited by Kara Rogers.—1st ed. p. cm.—(The Britannica guide to the world’s most influential people) “In association with Britannica Educational Publishing, Rosen Educational Services.” Includes index. ISBN 978-1-61530-040-2 (eBook) 1. Science—Popular works. 2. Science—History—Popular works. 3. Scientists— Biography—Popular works. I. Rogers, Kara.
    [Show full text]