Electricity (eBook)

Front Cover 1
Electricity 4
Copyright Page 5
Table of Contents 8
Preface 6
CHAPTER 1. CURRENT 12
Electrons 12
Current and Voltage 14
Ohm's Law 17
Simple Circuits 20
Summary 21
CHAPTER 2. RESISTANCE 23
Internal Resistance 24
Effect of Temperature 26
Resistivity 28
Fixed Resistors 31
Variable Resistors 32
Resistors in Series and in Parallel 34
Series–Parallel Circuits 37
Kirchhoff's Laws 39
Measurement of Resistance 42
Wheatstone Bridge 43
Summary 47
CHAPTER 3. ELECTROHEAT 49
Joule's Law 50
Electricity Bills 53
Kilowatt-hour Meter 54
Heating Effect of Current 55
Fuses 55
Appliances 57
Summary 60
CHAPTER 4. ELECTROMAGNETICS 61
Domain Theory 61
Magnetic Fields 63
Electrical Units 65
Field Round a Conductor 66
Electromagnets 70
Magnetic Circuits 73
Hysteresis 77
Summary 80
CHAPTER 5. ELECTROCHEMISTRY 82
Ions 82
Electrolysis of Sodium Chloride 83
Electrolysis of Water 84
Electroplating 86
Laws of Electrolysis 88
Batteries and Cells 90
Simple Cell 91
Polarization 93
The Dry Cell 93
Storage Batteries 95
Summary 99
CHAPTER 6. ELECTROMAGNETIC FORCES I: THE MOTOR EFFECT 100
SI units and their C.G.S. equivalents 102
Direction of Magnetic Force 102
Moving-Coil Galvanometer 103
Electric Motors 108
Back E.M.F. 110
Summary 113
CHAPTER 7. ELECTROMAGNETIC FORCES II: THE GENERATOR EFFECT 115
Induced E.M.F 118
Lenz's Law 119
The Generator Principle 120
D.C. Generator 123
Self-Inductance 124
Magnitude of the Back E.M.F. 127
Mutual Inductance 128
Eddy Currents 131
Summary 132
CHAPTER 8. ALTERNATING CURRENT 134
The Transformer 135
Power Transmission 140
Three-Phase Current 141
Skin Effect 142
Resistance in A.C. Circuits 144
R.M.S. Values 145
Hot-Wire Ammeter 146
Rectification of A.C. 146
Half-Wave Rectifier 150
Full-Wave Rectifier 151
Bridge Circuit 151
Summary 152
CHAPTER 9. CAPACITORS AND INDUCTORS 154
Capacitors 154
Capacitors in Series 157
Capacitors in Parallel 158
Capacitors in A.C. Circuits 159
Inductors 160
Inductors in Series and in Parallel 160
Inductive Reactance 163
Smoothing Circuits 164
Crossover Network 164
Reactance and Frequency 165
Summary 173
CHAPTER 10. ALTERNATING-CURRENT CIRCUITS 175
R–L–C Series Circuit 177
Impedance 179
Parallel Circuits 182
Power in A.C. Circuits 185
Resonance 188
Series Resonant Circuit 188
Frequency Meter 189
Q Factor 190
Parallel Resonant Circuit 190
Summary 193
CHAPTER 11. A.C. GENERATORS AND MOTORS 195
A.C. Motors 200
Linear Motor 203
Single-Phase Motors 203
Summary 205
CHAPTER 12. OTHER METHODS OF GENERATING E.M.F. 206
M.H.D. 206
Nuclear Battery 207
Thermoelectric Effect 208
Photoelectric Effect 210
Piezoelectric Effect 211
Electrostatic Generators 212
What Next? 214
TABLE OF NATURAL TRIGONOMETRIC FUNCTIONS 215
APPENDIX: GLOSSARY OF TERMS USED IN ELECTRICITY 220
REVISION QUESTIONS 230
INDEX 238