PHYSICS M.P. LORD MACMILLAN REFERENCE BOOKS

Transcription

1 PHYSICS

2 PHYSICS M.P. LORD M MACMILLAN REFERENCE BOOKS

3 The Macmillan Press Ltd, 986 All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission. No paragraph of this publication may be reproduced, copied or transmitted save with written permission or in accordance with the provisions of the Copyright Act 956 (as amended). Any person who does any unauthorised act in relation to this publication may be liable to criminal prosecution and civil claims for damages. First published 986 by THE MACMILLAN PRESS LTD London and Basingstoke Associated companies in Auckland, Delhi, Dublin, Gabornoe, Hamburg, Harare, Hong Kong, Johannesburg, Kuala Lumpur, Lagos, Manzini, Melbourne, Mexico City, Nairobi, New York, Singapore, Tokyo British Library Cataloguing in Publication Data Lord, M.P. Macmillan dictionary of physics. I. Physics-Dictionaries I. Title 530'.03'2 QC5 ISBN ISBN (ebook) DOl 0.007/ The paperback edition of this book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, resold, hired out, or otherwise circulated without the publisher's prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser. Photoset by Styleset Limited, Warminster, Wiltshire

4 Contents Preface Notes on use Table : Base and supplementary SI units Table 2 : Derived SI units with special names Table 3 : Prefixes used with SI units Table 4 : Symbols and SI units for some physical quantities Table 5 : Fundamental constants in SI units Table 6 : Conversion factors for some other units Table 7 : The Greek alphabet Dictionary Further reading suggestions vii ix X xi xii xii xvi xvii XX 33

5 Preface This Dictionary is an enlarged and updated version of the Physics content of a Dictionary of Physical Science edited by Dr John Daintith, Pan Books 978. It is hoped that the book, which contains over 4000 entries and about 200 line drawings, will be of use to Physics students at first year undergraduate and lower levels, and also to amateur enthusiasts and lay persons. The aim is to state essential principles of the subject clearly and concisely and to cover topics, having a Physics content, from other sciences, including medical science. I wish to thank my husband, Professor Arthur M. James for many interesting discussions and much forbearance during the compilation. I express my appreciation to the staff of Macmillan Reference Books for their help and encouragement and am indebted also to all the referees, especially Valerie Illingworth who, in addition, edited the manuscript.

6 ix Notes on Use Many, but not all, of the head words defined in the dictionary are shown in small capitals when they occur in another entry; so, if a word, not appearing in small capitals causes difficulty, it could be helpful to try looking it up. For ease of reference any term whose description appears within an entry is usually italicized. For example, the entry for drift tube is See LINEAR ACCELERATOR. In the entry linear accelerator, drift tube is defined. See also in an entry refers the reader to an entry which has some relevance to the one being read. Some units appear as headwords and also, in the tables at the front of the dictionary.

7 xi Table l. Base and supplementary SI units Physical Quantity Unit Name (base) Unit Symbol amount of substance current length luminous intensity mass thermodynamic temperature time plane angle solid angle mole ampere metre candela kilogramme kelvin second radian steradian (supplementary) mol A m cd kg K s rad sr Table 2. Derived SI units with special names Quantity Symbol Unit Name Unit Name Unit Symbol capacitance c A2 s4 kg- m-2 charge Q As conductance G A2 s3 kg- m-2 energy E kg s-2 force F kg m s-2 frequency v,f s- illuminance E.,E cd sr m-2 inductance, L kg m2 s-2 A-2 self inductance, M kg m2 s-2 A-2 mutual luminous 4>., 4> cd sr flux magnetic 'I' kg m2 s-2 A- flux magnetic B kg s-2 A- induction potential v kg m2 s-3 A- difference power p kg m2 s-3 pressure p kg m- s-2 resistance R,r kg m2 s-3 A-2 farad coulomb siemens joule newton hertz lux henry henry lumen weber tesla volt F c s J N Hz lx H H lm Wb T v w watt pascal Pa ohm 0

8 xii Table 3. Prefixes used with SI units Factor Prefix Symbol 0- deci- d 0-2 centi- c 0-3 milli- m 0-6 micro- 0-9 nano- n 0-2 pi co- p 0-s femto- f 0-8 atto- a 0 deca- da ()2 hecto- h 03 kilo- k ()6 mega- M ()9 giga- G 02 tera- T lois peta- p 08 exa- E Table 4. Symbols and SI Units for some physical quantities Name of quantity Symbol SI unit absorptance a acceleration a m s-2 angular frequency (J) Hz= s- angular momentum L Js angular velocity (J) rad s- area A,S m2 atomic number, proton number Bohr magneton s Am2 bulk modulus K Nm-2 charge, volume density of p cm-3 compressibility K,k N- m2 cross section a m2 Curie temperature 6c, Tc K decay constant A. s-i degeneracy (multiplicity) of an energy level g density p kg m-3 Dirac constant f J s z

9 xiii Table 4 (contd) Name of quantity Symbol SI Unit efficiency electric displacement D C m-2 electric field strength E vm- electric flux c electric polarization "' p C m-2 electric susceptibility Xe I electromotive force E v emissivity e I enthalpy H J entropy s J K- Gibbs function G J half life Tv, ty, s Hamiltonian function H J heat capacity: at constant pressure Cp JK- heat capacity: at constant volume Cv JK- Helmholtz function A,F J impedance, electric z n internal energy U,E J irradiance E.,E J m-2 Joule-Kelvin coefficient J. N- m2 K kinematic viscosity v m2 s- kinetic energy T,Ek,K J Lagrangian function L J linear absorption coefficient a m- linear attenuation (extinction) coefficient J. m- linear expansivity a K- luminance Lv,L cd m-2 luminous emittance M,M lm m-2 magnetic field strength H Am- magnetic moment m Am2 magnetic quantum number M, m; I magnetic susceptibility X. Xm magnetization M Am- magnetomotive force Fm A

10 xiv Table 4 (contd) Name of quantity Symbol SI Unit mass number, nucleon number A mean free path A., I m mean life "C s moment of inertia kg m2 momentum p Ns Neel temperature 9N,TN K neutron number N I nuclear magneton J.IN Am2 nuclear radius r m nuclear spin quantum number I,J osmotic pressure n Nm-2 packing fraction f period T s permeability, absolute J.l Hm- permittivity, absolute e Fm- Planck function y JK- polarizability a,y C m2 V-l potential energy EP, V, q, J principal quantum number n, ni quantity of heat q,q J radiance Le,L W m-2 sr- radiant excitance Me,M wm-2 radiant flux, radiant power q,e q, w radiant intensity /e, I Wsr- radioactivity A Bq* reactance X n reflection factor p I refractive index n I relative atomic mass Ar I relative density d I relative permeability llr I relative permittivity (dielectric constant) er I relaxation time "C s resistivity p Om Reynolds number (Re) I *See RADIATION UNITS

11 XV Table 4 (contd) Name of quantity Symbol Sf Unit shear modulus G Nm-2 specific heat capacity: at constant pressure cp J kg- K- specific heat capacity: at constant volume Cv J kg- K- specific optical rotatory power am rad m2 kg- specific volume v m3 kg- speed u m s- spin quantum number S,s surface tension y,a Nm- susceptance B s thermal conductivity A Wm- K- thermal diffusivity a m2 s- torque T Nm transmittance t" viscosity, coefficient of kg m- s- volume V,v m3 wavelength A m wave number a m- weight G N work w,w J work function <I> J Young's modulus E Nm-2

12 xvi Table 5. Fundamental constants in SI units Constant Symbol Value acceleration due to gravity (standard value) g m s-2 Avogadro constant NA orl x Q23 moi-l Boltzmann constant k X w- 23 J K-l charge on electron e X IQ-9 C charge on proton -e X IQ-9 C electric constant Bo x 0-2 F m- electronic radius r x IQ-5 m Faraday constant F x 04 C moi-l fine structure constant a X IQ-3 gravitational constant G x 0- N m2 kg-2 Loschmidt's number N x Q25 m-3 magnetic constant J.lo x IQ-6 H m- Planck constant h X IQ-34 J S rest mass of electron me X IQ-3 kg rest mass of neutron mn X IQ-27 kg rest mass of proton mp X IQ-27 kg Rydberg constant R x 07 m- speed of light c x 08 m s- Stefan's constant 0' x w-s W m-2 K-4 universal gas constant R J K- moi-

13 xvii Table 6. Conversion factors for some other units A Length m em in metre centimetre O.Ql inch foot yard km mile kilometre mile nautical mile ft n. mile yd light year = x Q5 metres = x 02 miles. astronomical unit =.496 x lqii metres. parsec = x 06 metres= light years. fathom = 6 feet. B Volume minim fluid drachm fluid ounce gill pint quart gallon /9600 pint 60 minims 8 fluid drachms 5 fluid ounces 4 gills dm3 2 pints 4 quarts dm3 gallon cubic foot cubic feet gallons m3 cubic decimetre (000 cc) is litre, although this name is not used in precision measurement. gallon (US) is equivalent to gallon (UK) c Velocity m s- kmh- mile h- metre per second kilometre per hour mile per hour foot per second ft s knot = nautical mile per hour = metre per second.

14 xviii Table 6 (contd) D Mass kg g lb long ton kilogramme gramme pound llong ton I X () X l() X l() X l() X l()-4 Apothecaries' Units of Mass grain scruple drachm ounce (apoth) pound (apoth) /7000 pound (avoirdupois) 20 grains 3 scruples 8 drachms 2 ounces (apoth) The grain (l/7000 pound avoirdupois) has the same value in the avoirdupois, troy and apothercaries' systems. Avoirdupois Units of Mass grain dram ounce pound stone quarter hundredweight ton gramme kilogramme l/7000 pound /256 pound 6 drams 6 ounces 4 pounds 2 stones 4 quarters 20 hundredweights ounces pounds g kg kg kg The avoirdupois hundredweight and ton are sometimes called the long hundredweight and long ton to distinguish them from the US measures, the short hundredweight (00 pounds) and short ton (2000 pounds). Troy Units of Mass grain carat pennyweight ounce (tr) pound (tr) hundredweight (tr) ton (tr) l/7000 pound (avoirdupois) 4 grains 6 carats 20 pennyweights 2 ounces (tr) 00 pounds (tr) 20 hundredweights (tr)

15 xix Table 6 (contd) E Force N kg dyne poundal lb newton kilogramme force dyne 0-5 poundal pound force X los x x X 0" X los oo x w x F Pressure N/m2 kg/cm2 lb/in2 atm newton per square metre kilogramme per square centimetre pound per square inch atmosphere x 0-s X X 03 omo X los X X newton per square metre = 0 dynes per square centimetre. bar = los newtons per square metre = atmosphere. torr = newtons per square metre = l/760 atmosphere. atmosphere= 760 mmhg = in Hg = ft water (all at 0 C). G Work and Energy J cain kwhr bturr joule calorie (IT) kilowatt hour 3.6 X X los I British thermal unit (n) joule = newton metre= watt second= 07 erg= ft lb. ejectronvolt = X I0-9 joule X X 0-6 I x X I X l

16 XX Table 7. The Greek Alphabet Letters Name Capital Small A a alpha B 3 beta r y gamma d 0 delta E epsilon z ~ zeta H T) eta e e theta I iota K K kappa A A. lambda M J..l mu N v nu 8 ~ xi 0 0 omicron n n pi p p rho :E 0 sigma T :" tau T \) upsilon <I> <> phi X X chi 'I' \jl psi 0 (J) omega