Part 1 Direct current
1 Basic physical concepts 3
Atoms 3
Protons, neutrons, and the atomic number 4
Isotopes and atomic weights 4
Electrons 5
Ions 5
Compounds 9
Molecules 10
Conductors 11
Insulators 11
Resistors 13
Semiconductors 14
Current 15
Static electricity 15
Electromotive force 16
Nonelectrical energy 18
Quiz 19
2 Electrical units 23
The volt 23
Current flow 24
The ampere 26
Resistance and the ohm 26
Conductance and the siemens 28
vii www.EngineeringBooksPDF.com
Power and the watt 29
Energy and the watt hour 31
Other energy units 33
ac Waves and the hertz 34
Rectification and fluctuating direct current 35
Safety considerations in electrical work 37
Magnetism 38
Magnetic units 39
Quiz 40
3 Measuring devices 44
Electromagnetic deflection 44
Electrostatic deflection 46
Thermal heating 47
Ammeters 48
Voltmeters 49
Ohmmeters 51
Multimeters 53
FET and vacuum-tube voltmeters 54
Wattmeters 54
Watt-hour meters 55
Digital readout meters 56
Frequency counters 57
Other specialized meter types 57
Quiz 60
4 Basic dc circuits 65
Schematic symbols 65
Schematic diagrams 67
Wiring diagrams 68
Voltage/current/resistance circuit 68
Ohm’s Law 69
Current calculations 69
Voltage calculations 71
Resistance calculations 71
Power calculations 72
Resistances in series 73
Resistances in parallel 74
Division of power 75
Resistances in series-parallel 75
Resistive loads in general 77
Quiz 77
5 Direct-current circuit analysis 82
Current through series resistances 82
Voltages across series resistances 83
viii Contents
www.EngineeringBooksPDF.com
Voltage across parallel resistances 85
Currents through parallel resistances 86
Power distribution in series circuits 88
Power distribution in parallel circuits 88
Kirchhoff’s first law 89
Kirchhoff’s second law 91
Voltage divider networks 92
Quiz 95
6 Resistors 99
Purpose of the resistor 99
The carbon-composition resistor 102
The wirewound resistor 103
Film type resistors 104
Integrated-circuit resistors 104
The potentiometer 105
The decibel 107
The rheostat 109
Resistor values 110
Tolerance 110
Power rating 110
Temperature compensation 111
The color code 112
Quiz 114
7 Cells and batteries 118
Kinetic and potential energy 118
Electrochemical energy 118
Primary and secondary cells 119
The Weston standard cell 120
Storage capacity 120
Common dime-store cells and batteries 122
Miniature cells and batteries 124
Lead-acid cells and batteries 125
Nickel-cadmium cells and batteries 125
Photovoltaic cells and batteries 127
How large a battery? 128
Quiz 130
8 Magnetism 134
The geomagnetic field 134
Magnetic force 135
Electric charge in motion 136
Flux lines 136
Magnetic polarity 137
Dipoles and monopoles 139
Contents ix
www.EngineeringBooksPDF.com
Magnetic field strength 139
Permeability 142
Retentivity 142
Permanent magnets 143
The solenoid 144
The dc motor 145
Magnetic data storage 146
Quiz 149
Test: Part 1 153
Part 2 Alternating current
9 Alternating current basics 165
Definition of alternating current 165
Period and frequency 165
The sine wave 167
The square wave 167
Sawtooth waves 167
Complex and irregular waveforms 169
Frequency spectrum 170
Little bits of a cycle 172
Phase difference 173
Amplitude of alternating current 173
Superimposed direct current 175
The ac generator 176
Why ac? 178
Quiz 178
10 Inductance 183
The property of inductance 183
Practical inductors 184
The unit of inductance 185
Inductors in series 185
Inductors in parallel 186
Interaction among inductors 187
Effects of mutual inductance 188
Air-core coils 189
Powdered-iron and ferrite cores 190
Permeability tuning 190
Toroids 190
Pot cores 192
Filter chokes 192
Inductors at audio frequency 193
Inductors at radio frequency 193
Transmission-line inductors 193
x Contents
TEAM
