MAGNETISM

PART I

MAGNETISM

CHAPTER I-MAGNETOSTATICS

(1) Historical Introduction.

(2) Natural and Artificial Magnets,

(3) Per- manent and Electromagnets.

(4) Magnetic Induction.

(5) Theories of Magnetism.

(6) The Inverse Square Law

(8) Field due

(7) Action of fa magnet in a uniform magnetic field. Magnet.

(9) Action of a Magnet in a Non-Uniform Field.

(10) to a Crossed Magnetic Fields.

(11) Deflection Magnetometer.

(12) Couples between Two Small Magnets.

(13) Forces between Two Small Magnets.

(14) Magnetic Potential.

(15) Potential due to a Magnet

(16) Potential and Field due to a uniformly magnetised sphere.

(17) Magnetic Shell.

(18) Gauss’s Theorem.

(19) Vibration Magnetometer.

CHAPTER II-TERRESTRIAL MAGNETISM

(20) The Earth’s Magnetic Field, Magnetic Elements.

(21) Absolute Deter- mination of H.

(22) Determination of Declination.

(23) Kew magnetometer.

(24) Determination of Dip.

(25) Variation in Magnetic Elements of the Earth.

(26) Magnetic Maps.

(27, Magnetographs.

(28) Theory of Terrestrial Magne- tism.

(29) Ship’s magnetism.

PART II

ELECTROSTATICS

CHAPTER III-ELECTROSTATIC PHENOMENA

(30) Early Electrical Experiments.

(31) Theories of Electricity.

(32) Inverse Square Law in Electricity.

(33) Electric Potential.

(34) Potential due to a Point Charge.

(35) Equipotential Surface.

(36) Potential due to a Uniformly Charged Sphere.

(37) Electric Capacity.

(38) Energy of a Charged Conductor.

(39) Sharing of Charges.

(40) Gauss’s Theorem.

(41) Electric Intensity due to a Uni- formly Charged Sphere.

(42) Electric Intensity due to a Charged Spherical Shell.

(43) Electric Intensity outside a Uniformly Charged Infinite Cylinder

(44) Elec- tric Intensity near an Infinite Plane Sheet of Charge.

(45) Electric Inte Intensity near Two Uniformly Charged Infinite Planes.

(46) Electric Intensity near a Charged Plane Conducting Sheet.

(47) Coulomb’s Law.

(48) Force on the Surface of a Charged Conductor.

(49) Energy per Unit Volume of the Medium.

(50) Lines of Force and Tubes of Induction.

(51) Electrical images,

(52) Electrostatic Gener- ators, Van de Graaff Generator, Linear Accelerator.

CHAPTER IV-CONDENSERS AND ELECTROMETERS

(53) Principle of the condenser.

(54) Spherical condenser.

(55) Cylindrical condenser.

(56) Parallel Plate condenser.

(57) Effect of Dielectric.

(58) Parallel Plate Condenser partly filled with Dielectric.

(59) Grouping of Condensers.

(60) Guard Ring Condenser.

(61) Types of Condensers.

(62) Electrometers.

(63) Kelvin’s Absolute or Attracted Disc Electrometer.

(64) Determination of Dielectric constant with an Attracted Disc Electrometer.

(65) Quadrant Electrometer.

(66) Comparison of Capacities or determination of dielectric constant.

(67) Capacity with the help of a Quadrant Electrometer by Kelvin’s Method.

(68) Deter- mination of Capacity by sharing of Charges.

(69) Silow’s method for determining dielectric constant of liquids.

(70) Measurement of Ionisation currents by Quadrant Electrometer.

(71) Other types of Electrometers, Dolezalek Electrometer, Compton Electrometer, Lindamann Electrometer, Simple String Electrometer, String Electrometer.

(72) Electrostatic Voltmeter.

(73) Diele Dielectric Constant of Liquids and Gases.

CHAPTER V-PRIMARY AND SECONDARY CELLS

(74) Historical Introduction.

(75) Voltaic Cell and its Defects.

(76) Primary Celis, Daniell Cell, Leclanche Cell, Dry Cell.

(77) Standard Cells.

(78) Clark Cell.

(79) Weston Cadmium Cell.

(80) Reversible Cell.

(81) Secondary Cells.

(82) Lead Accumulators.

(83) Edison’s Cell.

(84) Summary of Important Cells.

CHAPTER VI-MAGNETIC EFFECT OF CURRENTS

(85) Effects of Electric Current.

(86) Magnetic Field due to an Electric Current, Cork Screw Rule, Right Hand Palm Rule, Ampere’s Rule.

(87) Laplace’s law, Field due to a long Linear Conductor.

(88) Field due to a Circular Current.

(89) Electromagnetic Unit of Current.

(90) Tangent Galvanometer.

(91) Sine Galvanometer.

(92) Field along the axis of a Circular Coil.

(93) Helmholtz Galvanometer.

(94) Sensitive Moving Magnet Galvanometers.

(95) Effect of Magnetic Field upon Current, Fleming’s L. H. Rule.

(96) Moving Coil Galvano- meter.

(97) Einthoven String Galvanometer.

(98) Moving Iron Galvanometer.

(99) Sensitiveness of a Galvanometer.

(100) Galvanometer Shunt.

(101) Ammeters and Voltmeters.

(102) Ohmmeter, Megger and Avometer.

CHAPTER VII-STEADY CURRENTS

(103) Ohm’s Law.

(104) Combination of Resistances.

(105) Specific Resistance.

(106) Grouping of Cells.

(107) Kirchhoff’s Laws.

(108) Application of Kirchhoff’s Laws to Wheatstone’s Bridge.

(109) Sensitiveness of the Wheat- stone’s Bridge.

(110) Maxwell’s Cyclic Current.

(111) Kelvin’s Method for Resistance of a Galvanometer.

(112) Mance’s Method for Internal Resistance of a Cell.

(113) Post Office Box.

(114) Metre Bridge.

(115) Carey Foster’s Bridge.

(116) Callendar and Griffith’s Bridge.

(117) Kelvin’s Double Bridge.

(118) Internal Resistance of an Accumulator.

(119) Potentiometer. (120) Types of Potentiometer.

(121) Uses of Potentiometer, Measurement of Large Potential Difference, Measurement of small Thermo-E.M.F.s., Measurement of Currents, Calibration of Ammeter and Voltmeter, Comparison of Resistances, Internal Resis- tance of a Cell.

CHAPTER VIII-HEATING EFFECT OF CURRENTS

(122) Conversion of Electrical Energy into Heat.

(123) Joules Laws.

(124) Callender and Barne’s Constant-flow Calorimeter.

(125) Hot-wire Instruments.

(126) Temperature of a Current Carrying Conductor.

(127) Applications of Heating Efect of Currents, Electric Stoves, Electric Furnaces, Safety Fuse, Electric Arc, Carbon Filament Lamps, Metal Filament Lamps, Photo Flash and Photo Flood Lamps, Mercury Arc Lamps: Efficiency of various Lamps.

CHAPTER IX-CHEMICAL EFFECT OF CURRENTS

(128) Electrolysis.

(129) Faraday’s Laws of Electrolysis, Electro-chemical Equivalent.

(130) The International Ampere, (131) Atomicity of Electricity

(132) Aplications of Electrolysis, Electroplating, Electrotyping, densers, Noden Valves. Valves

(133) Electrolyte Conduction, Specific Conductivity, Stroud and Migration enderson’s Method, of Ions, Mobility Kohlrausch’s Method, Types of Ions, of cells.

(134) Ionic Velocities, Transport Number, Degree of Dissociation, Molecular Conductivity.

(135) Dissociation Theory, Debye Theory. Huckel

CHAPTER X-THERMO-ELECTRICITY

(136) Seebeck Effect.

(137) Thermo-electric Series.

(138) Peltier Effect.

(139) Laws of Thermo-electricity.

(140) Thomson Effect, Thomson Coefficient.

(141) Thermo-electric Power.

(142) Thermo-electric Diagram.

(143) Appli- cations, Thermopile, Boy’s Radio-micrometer, Duddell’s Thermo-Galvanometer, Thermo-milliammeter, Thermo-electric Pyrometer.

(144) Pyro and Piezo Electricity.

CHAPTER XI-ELECTROMAGNETICS

(145) Ampere’s Theorem.

(146) Potential and Magnetic Field along the axis of a Circular Current.

(147) Field due to Solenoidal Current.

(148) Work done by a Unit pole, Line Integral of Magnetic Field.

(149) Magnetic field due to Straight Current.

(150) Field due to a Toroid.

(151) Force on a current in a Magnetic Field.

(152) Action of Current on Current.

(153) Kelvin’s Ampere Balance.

(154) Kelvin’s Watt Balance.

(155) Watt Meter.

(156) Energy Meter.

(157) Moving Magnet Ballistic Galvanometer.

(158) Moving Coil Ballistic Galvanometer.

(159) Dead-beat and Ballistic Galvanometers.

(160) Damping, Logarithmic Decrement.

(161) Calibration of Ballistic Galvanometer.

(162) Com- parison of E.M.F.s and Capacities.

(163) Practical Applications of Electromagne- tism.

(164) Electric Telegraphy.

(165) Electric Telephony.

(166) Loudspeaker.

(167) Recording and Reproduction of sound.

CHAPTER XII-MAGNETIC PROPERTIES OF MATERIALS

(168) Magnetic Induction, Permeability.

(169) Para-Dia-and Ferromagnetic Substances, Curie Law.

(170) Methods of Finding and μ.

(171) Magnetometer method.

(172) Ballistic Method.

(173) Bar and Yoke Method.

(174) Hysteresis, Energy loss due Energy to Hysteresis, Hysteresis loss from I-H and B-H cycles.

(175) Ewing’s hysteresis tester.

(176) Demagnetisation.

(177) Uses of Hysteresis Curves.

(178) Magnetic Circuit, Magnetomotive force, Reluctance.

(179) Curie Balance.

(180) Production of strong Magnetic Fields.

(181) Barkhausen Effect and Magne- tostriction, Magnetostriction Oscillator, Villari Effect.

(182) Theories of Magne- tisation, Modern Electron Theory, Stern Gerlach Experiment.

(183) Diamagnetism.

(184) Paramagnetism.

(185) Ferromagnetism.

CHAPTER XIII-ELECTRO-MAGNETIC INDUCTION

(186) Electromagnetic Induction, Laws of Induction, Lenz’s Law, Fleming’s Right Hand Rule.

(187) Earth Inductor, Measurement of H, V and 6.

(188) Standard Magnetic Flux, Hibbert Magnetic Standard, Grossot’s Fluxmeter.

(189) Measurement of strong Magnetic fields.

(190) Induced currents, Speedo- rrents, meter.

(191) Self-Inductance, Units, Coefficient of Self-inductance.

(192) Self- inductance of a solenoid.

(193) Self-inductance of two Coaxial Cylinders.

(194) Growth and Decay of Currents.

(195) Measurement of Self-inductance.

(196) Comparison of Self-inductances.

(197) Charge and Discharge of a Condenser.

(198) Measurement of High Resistance by Leakage.

(199) Comparison of Capaci- ties (200) Mutual Inductance.

(201) Mutual inductance of concentric solenoids.

(202) Measurement of Mutual inductance.

(203) Circuit with Inductance, Capacity and Resistance (Charge).

(204) Circuit with Inductance, Capacity and Resistance (Discharge).

(205) Practical Applications of Electromagnetic Induction.

(206) Induction Coil, Mercury Interrupter.

(207) Coil Ignition set for a Car. (208) Electrically maintained Tuning Fork.

(209) A. C. Dynamo, Rotor Armature Type, Rotor Field Type, Two and Three Phase Generators, Speed and Frequency.

(210) Distribution of 3 phase-current.

(211) D. C. D. C. Dynamo, Series wound, Shuntwound, Compound wound Dynamos, Efficiency.

(212) D.C. Motor, Series wound, Shunt wound, Compound wound Motors.

(213) A.C. Motors for clocks.

CHAPTER XIV-ALTERNATING CURRENTS

(214) Relative merits of A.C. and D.C.

(215) Virtual Current and E.M.F.

(216) Circuit with Inductance and Resistance; Impedence and Reactance.

(217) Power in A.C. Circuit. (218) Measurement of Inductance.

(219) A.C. Wattmeter.

(220) Measurement of A.C. Frequency.

(221) Circuit containing Capacity, Inductance and Resistance.

(222) Resonance Circuits.

(223) Choke.

(24) Transformer, Long distance Power Transmission.

(225) Vibration Galvano- meter

(226) Repulsion due to an A.C. Electromagnet.

(227) Rectifiers, Full waves, Electrolytic, Metal, and Mercury Arc Rectifiers.

(228) Skin Effect.

(229) Tesla Coil.

(230) Rotating Magnetic Fields, Single phase A.C. Motor.

CHAPTER XV-UNITS AND DIMENSIONS AND INTERNATIONAL STANDARDS

(231) Systems of Units.

(232) Dimensions.

(233) Dimensions of Units in Electromagnetic System.

(234) Dimensions of Units in Electrostatic System.

(235) Relation between e.m. and e.s. units.

(236) Practical Units, Inter-relation of Units.

(237) International Practical Units.

(238) The M.K.S. System of Units, The M.K.O.S. System.

(239) Absolute Determination of the Ohm (Lorenz’s Method).

CHAPTER XVI-CONDIDUCTION OF ELECTRICITY THROUGH GASES AND POSITIVE RAYS

(2.0) Discharge at Atmospheric Pressure, Paschen’s Law.

(241) Ionisation of Gases.

(242) Experimental Determination of Ionisation Potential of Gases.

(243) Experimental Determination of Resonance Potential of Gases.

(244) Discharge of Electricity through Gases at low Pressure.

(245) Applications of Discharge Tube Phenomena, Neon Lamp, Positive Column Tubes, Sodium Vapour Lamp, Mercury Vapour Lamps, Fluorescent Tubes.

(246) Cathode Rays.

(247) Cathode Ray Oscillograph, Hysterisis Curve on CRO Screen, Applications.

(248) Deter- mination of e/m.

(249) Millikan’s Method.

(250) Mass of Electron.

(251) Mass of Hydrogen ion.

(252) Positive Rays.

(253) Thomson’s Mass Spectrograph.

(254) Aston’s Mass Spectrograph.

(255) Bainbridge’s Mass Spectrograph.

(256) Isotopes.

CHAPTER XVII-X-RAYS AND PHOTO-FLECTRICITY

(257) Discovery of X-rays.

(258) Production of X-rays.

(259) Coolidge X-ray Tube,

(260) Properties of X-rays.

(261) Practical Applications of X-rays.

(262) Origin of X-rays, X-ray Spectra.

(263) Bragg’s Spectrograph.

(264) Interac- tion of X-rays with Matter.

(265) Absorption ption of X-rays, Compton Effect, Raman Effect.

(266) Laue Spots.

(267) Betatron.

(268) Photo-electric Effect. Laws of Photo- electric Emission, Einstein’s Equation.

(269) Photo-electric Cell.

(270) Other types of Photo Cells.

(271) Applications of Photo-electric Cell, Cinematograph, Burglar’s Alarm, Television, Microphotometers, Foot-Candle Meters.

CHAPTER XVIII-NUCLEAR PHYSICS AND COSMIC RAYS

(272) Types of Nuclear Disintegration.

(273) Radioactivity, Becquerel Rays.

(274) Methods of Detecting Charged Particles, Spinthariscope, Gold-leaf Electroscope, Geiger-Muller Counter, Wilson Cloud Chamber. 

(275) x-rays

(276) β-rays.

(277) y-rays.

(278) Radio-active Transformations, The Uranium Radium Series, Actinium Series, Thorium Series.

(279) Soddy Fajan’s Displacement Law.

(280) Kutherford and Soddy-theory of Radio-active Disintegration, Radio- active Constant, Average Life of an atom.

(281) Artificial Nuclear Disintegration, Discovery of Proton.

(282) Neutrons.

(283) Structure of the Nuclear Potential Barrier.

(284) Induced Radio-activity.

(285) Production of High Speed Particles, Van de Graaff Generator, Cockcraft and Walton Voltage Multiplier, Cyclotron.

(286) Nuclear Fission.

(287) Isotopes of Uranium.

(288) Atomic Energy.

(289) Trans-Uranium Elements.

(290) Uranium Pile.

(291) Atom Bomb.

(292) Hydrogen Bomb.

(293) The Sun’s Energy.

(294) Cosmic Rays, Latitude Effect, Secondary Cosmic Rays, showers.

(295) Positron, Electron Pairs.

(296) Mesons.

(297) Origin of Cosmic Rays.

CHAPTER XIX-STRUCTURE OF THE ATOM

(298) Early views on Atomic Structure.

(299) Bohr’s Theory of the Structure of Atom.

(300) The Hydrogen Series.

(301) Applications of Bohr’s Theory, Absorption of Spectral Lines, Size of Hydrogen Atom.

(302) Sommerfeld-Wilson’s Theory.

(303) Deuteron or Heavy Hydrogen.

(304) Bohr-Stoner Scheme of the Building up of Atoms.

(305) Ionisation and Resonance Potentials.

(306) The Bohr Magneton.

(307) De Broglie Waves, Wave Mechanics, Davisson and Garmer’s Experiment, G. P. Thomson’s Experiment, Heisenberg’s Uncertainty Principle.

(308) Electron Microscope.

(309) The Quantum Theory.

(310) Zeeman Effect, Transverse Zeeman Effect, Stark Effect, Faraday Effect, Kerr Effect.

CHAPTER XX-PRINCIPLES OF RADIO COMMUNICATIONS

(311) Electromagnetic Waves, Hertz Experiments, Electromagnetic Spectrum, Experiments of Sir Oliver Lodge, Marconi’s Experiment.

(312) Wireless Tele- graphy.

(313) Thermionic Emission.

(314) The Diode, Characteristics of a Diode, Applications of a Diode, Half-wave Rectifier, Full Wave Rectifier, Diode as a Detector.

(315) The Triode, Characteristic of a Triode.

(316) Coefficients of a Triode

(317) Applications of a Triode.

(318) Triode as an Amplifier.

(319) Triode as an Oscillator.

(320) Triode as a Modulator.

(321) Triode as a Detector.

(322) Sidebands.

(323) Transmitters.

(324) Reception of Radio Waves Crystal Receiver, One Valve Receiver. Two Valve Receiver, Three Valve Receiver.

(325) Broadcast Receivers.

(326) Propagation of Radio Signals, Skip Distance, Fading.

(327) Production of Very Short Radio Waves.

(328) Magnetron.

(329) Radar.

(330) Principles of Television.

(331) Iconoscope, Kinescope.

(332) The Principles of Screening, Electric Screens, Magnetic Screens, Screening of Radio Frequencies, Screened leads.