Chapter 18: Oscillating Currents
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Source Metadata
Section titled “Source Metadata”| Field | Value |
|---|---|
| Source | Theory and Calculation of Electric Circuits |
| Year | 1917 |
| Section ID | theory-calculation-electric-circuits-chapter-18 |
| Location | lines 31657-33200 |
| Status | candidate |
| Word Count | 3555 |
| Equation Candidates In Section | 0 |
| Figure Candidates In Section | 0 |
| Quote Candidates In Section | 0 |
Opening Source Excerpt
Section titled “Opening Source Excerpt”CHAPTER XVIII OSCILLATING CURRENTS Introductioii 181. An electric current varying periodically between constant maximum and minimum values — that is, in equal time intervals repeating the same values — is called an alternating current if the arithmetic mean value equals zero; and is called a pulsating cur- rent if the arithmetic mean value differs from zero. Assuming the wave as a sine curve, or replacing it by the equivalent sine wave, the alternating current is characterized by the period or the time of one complete cyclic change, and the amplitude or the maximum value of the current. Period and amplitude are constant in the alternating current. A very important class are the currents of constant period, but geometrically varying amplitude; that is, currents in which the amplitude of each following wave bears to that ofSource-Located Theme Snippets
Section titled “Source-Located Theme Snippets”Magnetism
Section titled “Magnetism”... , resist- ance as well as conductance have a negative term added, which depends on the decrement a. Such a negative resistance repre- sents energy production, and its meaning in the present case is, that with the decrease of the oscillating current and voltage, their stored magnetic and dielectric energy become available. Circuits of Zero Impedance 190. In an oscillating-current circuit of decrement, a, of resistance, r, inductive reactance, x, and condensive reactance, Xc, the impedance was represented in symbolic expression by or numerically by ...Waves / transmission lines
Section titled “Waves / transmission lines”... en constant maximum and minimum values — that is, in equal time intervals repeating the same values — is called an alternating current if the arithmetic mean value equals zero; and is called a pulsating cur- rent if the arithmetic mean value differs from zero. Assuming the wave as a sine curve, or replacing it by the equivalent sine wave, the alternating current is characterized by the period or the time of one complete cyclic change, and the amplitude or the maximum value of the current. Period and amplitude are constant in the alternating current ...Impedance / reactance
Section titled “Impedance / reactance”... he exponential decrement of the oscillating wave, a the angu- lar decrement of the oscillating wave. The oscillating wave can be represented by the equation, E = e€"***'^«cos(« - 6). In the example represented by Figs. 130 and 131, we have A = 0.4, a = 0.1435, a = 8.2°. Impedance and Admittance 184. In complex imaginary quantities, the alternating wave, z = e cos (0 — 6)^ is represented by the symbol, fl = e(cos d — j sin ^) = ei — je2» By an extension of the meaning of this symbolic expression, the oscillating wave, JS? = tt"*** cos {<t> — 6) ...Complex quantities
Section titled “Complex quantities”... . Since A^-" = A^A-" = «-w, where « = basis of natural logarithms, the current may be expressed, 7 = it-*" cos (2 irft - fi) = M"°* cos ( *- 9), \. "~>- \ '^"r-- \ _,^ _ .' m I »\ «n i^^ ^gEp-i t v V ^ ^^ZE" 0.dll....J^E "/■ , ^ t t^i"t T K ..-aJ & ( f^^^^m C\ V ^^-^^1 %i/ii^imm;^:,y-.'-.//.'d Fia. 131. where ^ = 2 )r/(; that is, the period is represented by a complete revolution. In the same way an oscillating e.m,f. will be represented by E = et"""* c ...Chapter-Local Concept Hits
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| Frequency | 6 | seeded |
| Light | 3 | seeded |
| Luminescence | 1 | seeded |
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Modern Engineering Reading Prompts
Section titled “Modern Engineering Reading Prompts”- Magnetism: Track flux, reluctance, permeability, magnetizing force, and loss language against modern magnetic-circuit terminology.
- Waves / transmission lines: Map Steinmetz’s wave and line language onto modern distributed constants, propagation velocity, standing waves, and reflections.
- Impedance / reactance: Translate historical opposition terms into modern impedance, admittance, conductance, susceptance, and complex-plane notation.
- Complex quantities: Track how Steinmetz preserves geometric rotation and quadrature while translating the same operation into symbolic form.
- Dielectricity / capacity: Check whether the passage treats capacity, condensers, displacement, or dielectric stress as field storage rather than only circuit algebra.
Ether-Field Interpretive Boundary
Section titled “Ether-Field Interpretive Boundary”- Magnetism: Centrifugal/divergent magnetic-field readings are interpretive overlays, not automatic historical claims.
- Waves / transmission lines: Standing/traveling wave passages may support richer field interpretations; the page keeps those readings separate from verified Steinmetz wording.
- Dielectricity / capacity: A Wheeler-style reading may emphasize dielectric compression, field stress, and stored potential, but this page treats that as interpretation unless Steinmetz explicitly says it.
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- Verify the chapter boundary and surrounding context.
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