Incandescent Lamp-filament. (See [Filament].)
India-rubber. (See [Caoutchouc] and [Gutta-percha].)
Indicator-card. The card used in galvanoscopes, volt and ampere meters, and other instruments. It is provided with a moving needle and is marked with a graduated scale.
Induced. Caused by induction, and not directly.
Induced Current. (See [Current, Induced].)
Inductance. That capacity of a circuit which enables it to exercise induction and create lines of force.
Inductance is the ratio between the total induction through a circuit to the current producing it.
Induction, Back. A demagnetizing force produced in a dynamo armature when a lead is given to the brushes. When the brushes are so set the windings on the armature are virtually divided into two sets: one a direct magnetizing set, the other a cross-magnetizing set which exerts a demagnetizing action on the other set. The position of the brushes on a dynamo or motor is indicated by their location, and if changed back induction will be the result.
Induction-coil. (See [Coil, Induction].)
Induction, Electro-magnetic. When negative and positive currents are brought towards each other against their material repulsive tendencies the result is work, or energy, and the consequent energy increases the intensity of both currents temporarily. The variations thus temporarily produced in the currents are examples of electro-magnetic induction. A current is surrounded by lines of force. The approach of two circuits—one negative, the other positive—involves a change in the lines of force about the secondary circuit. Lines of force and current are so intimately connected that a change in one compels a change in the other. Therefore, the induced current in the secondary may be attributed to the change in the field of force in which it lies. The inner and outer coils of wire about the soft iron wire composing an induction-coil are the best and simplest examples of electro-magnetic induction.