viii CONTENTS 



PAGE 



41. Unit of Electromotive Force. 



42. Force Exerted by a Magnetic Fieid on an Electric Circuit. 



43. Transformation of Mechanical Energy to Electrical Energy. 



44. Intensity of Magnetic Fields Produced by Electric Currents. 



45. Magnetomotive Force of a Solenoid. 



46. Examples. 



47. Energy Stored in the Magnetic Field. 



48. Stress in the Magnetic Field. 



49. Permeability Curves. 



50. Hysteresis. 



CHAPTER III. 

 ELECTRIC CIRCUITS 75 



51. Ohm's Law. 



52. Joule's Law. 



53. Resistance. 



54. Conductance. 



55. Effect of Temperature on Resistance. 



56. Resistance of Conductors. 



57. Drop of Voltage and Loss of Power in a Distributing Circuit. 



58. Current-carrying Capacity of Wires. 



59. Examples. 



60. Kirchoff's Laws. 



61. Resistances in Series. 



62. Resistances in Parallel. 



63. The Potentiometer. 



64. Inductance. 



65. Inductance of Circuits containing Iron. 



66. Example. 



67. Mutual Inductance and Self-Inductance. 



68. Self-Inductance of Continuous-current Circuits. 



69. Example. 



70. Example. 



71. The Sine Wave of Electromotive Force and Current. 



72. The Average Value of a Sine Wave. 



73. The Effective Value of a Sine Wave. 



74. Inductance in Alternating-current Circuits. 



75. Resistance and Reactance in Series. 



76. Capacity in Alternating-current Circuits. 



77. Resistance and Condensive Reactance in Series. 



78. Resistance, Inductance and Capacity in Series. 



79. Vector Representation of Harmonic Quantities. 



80. Power and Power Factor. 



81. Examples. 



82. Numerical Examples. 



83. Circuit Constants. 



84. Example. 



85. Rectangular Coordinates. 



86. Examples in Rectangular Coordinates. 



87. Kirchoff's Laws Applied to Alternating-current Circuits. 



CHAPTER IV. 

 DIRECT-CURRENT MACHINERY 144 



88. The Direct-current Dynamo. 



89. Yoke. 



90. Pole Pieces. 



91. Armature core. 



92. Armature Winding. 



93. Ring Windings. 



