Theory Section 7: Inductance in Alternating-current Circuits
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Source Metadata
Section titled “Source Metadata”| Field | Value |
|---|---|
| Source | Theoretical Elements of Electrical Engineering |
| Year | 1915 |
| Section ID | theoretical-elements-electrical-engineering-section-07 |
| Location | lines 2250-2717 |
| Status | candidate |
| Word Count | 1937 |
| Equation Candidates In Section | 18 |
| Figure Candidates In Section | 1 |
| Quote Candidates In Section | 0 |
Opening Source Excerpt
Section titled “Opening Source Excerpt”7. INDUCTANCE IN ALTERNATING-CURRENT CIRCUITS 34. An alternating current i = IQ sin 2irft or i — I0 sin 0 can be represented graphically in rectangular coordinates by a curved line as shown in Fig. 10, with the instantaneous values FIG. 10. — Alternating sine wave. i as ordinates and the time t, or the arc of the angle corresponding to the time, 6 = 2irft, as abscissas, counting the time from the zero value of the rising wave as zero point. If the zero value of current is not chosen as zero point of time, the wave is represented by i = /0 sin 2 IT/ (t - t'), or i = /osin (6 — 8'), where tf and 6' are respectively the time and the corresponding angle at which the current reaches itsSource-Located Theme Snippets
Section titled “Source-Located Theme Snippets”Impedance / reactance
Section titled “Impedance / reactance”... sine wave of current. This e.m.f. is called the counter e.m.f. of inductance. It is .'•'• '•••• e'*=-Ljt = - 2 TT/L/O cos 2 irft. It is shown in dotted line in Fig. 11 as e'2. The quantity 2 irfL is called the inductive reactance of the circuit, and denoted by x. It is of the nature of a resistance, and expressed in ohms. If L is given in 109 absolute units or henrys, x appears in ohms. The counter e.m.f. of inductance of the current, i = /o sin 2 irft = ...Magnetism
Section titled “Magnetism”... and the corresponding angle at which the current reaches its zero value in the ascendant. If such a sine wave of alternating current i = IQ sin 2 irft or i = IQ sin 6 passes through a circuit of resistance r and induc- tance L, the magnetic flux produced by the current and thus its interlinkages with the current, iL = IoL sin 0, vary in a wave 32 ELEMENTS OF ELECTRICAL ENGINEERING line similar also to that of the current, as shown in Fig. 11 as $. The e.m.f. gener ...Waves / transmission lines
Section titled “Waves / transmission lines”... ATING-CURRENT CIRCUITS 34. An alternating current i = IQ sin 2irft or i — I0 sin 0 can be represented graphically in rectangular coordinates by a curved line as shown in Fig. 10, with the instantaneous values FIG. 10. — Alternating sine wave. i as ordinates and the time t, or the arc of the angle corresponding to the time, 6 = 2irft, as abscissas, counting the time from the zero value of the rising wave as zero point. If the zero value of current is not chosen as zero ...Alternating current
Section titled “Alternating current”7. INDUCTANCE IN ALTERNATING-CURRENT CIRCUITS 34. An alternating current i = IQ sin 2irft or i — I0 sin 0 can be represented graphically in rectangular coordinates by a curved line as shown in Fig. 10, with the instantaneous values FIG. 10. — Alternating sine wave. i as ...Chapter-Local Concept Hits
Section titled “Chapter-Local Concept Hits”| Concept Candidate | Hits In Section | Status |
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| Frequency | 1 | seeded |
Chapter-Local Glossary Hits
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| No chapter-local term hits yet | - | - |
Equation Candidates
Section titled “Equation Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
|---|---|---|
theoretical-elements-electrical-engineering-eq-candidate-0283 | 7. INDUCTANCE IN ALTERNATING-CURRENT CIRCUITS | line 2250 |
theoretical-elements-electrical-engineering-eq-candidate-0284 | 34. An alternating current i = IQ sin 2irft or i — I0 sin 0 | line 2252 |
theoretical-elements-electrical-engineering-eq-candidate-0285 | curved line as shown in Fig. 10, with the instantaneous values | line 2254 |
theoretical-elements-electrical-engineering-eq-candidate-0286 | FIG. 10. — Alternating sine wave. | line 2257 |
theoretical-elements-electrical-engineering-eq-candidate-0287 | to the time, 6 = 2irft, as abscissas, counting the time from the | line 2260 |
theoretical-elements-electrical-engineering-eq-candidate-0288 | i = /0 sin 2 IT/ (t - t’), | line 2266 |
theoretical-elements-electrical-engineering-eq-candidate-0289 | or i = /osin (6 — 8’), | line 2267 |
theoretical-elements-electrical-engineering-eq-candidate-0290 | If such a sine wave of alternating current i = IQ sin 2 irft or | line 2271 |
Figure Candidates
Section titled “Figure Candidates”| Candidate ID | OCR / PDF-Text Candidate | Source Location |
|---|---|---|
theoretical-elements-electrical-engineering-fig-011 | e\ = — r/0 sin 0, opposite in phase to the current, shown as e\ in dotted line in Fig. 11. The counter e.m.f. of resistance and the e.m.f. consumed by resistance have the same r… | line 2374 |
Hidden-Gem Quote Candidates
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| No chapter-local candidates yet | - | - |
Modern Engineering Reading Prompts
Section titled “Modern Engineering Reading Prompts”- Impedance / reactance: Translate historical opposition terms into modern impedance, admittance, conductance, susceptance, and complex-plane notation.
- 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.
- Alternating current: Compare Steinmetz’s AC language with modern sinusoidal steady-state analysis, RMS quantities, phase, and phasor notation.
- Field language: Read for whether field language is mechanical, geometrical, causal, descriptive, or simply a convenient engineering model.
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.
- Field language: Field-pressure or field-gradient interpretations can be explored here only after the explicit source passage and modern engineering translation are kept distinct.
Promotion Checklist
Section titled “Promotion Checklist”- Open the full source text and the scan or raw PDF.
- Verify the chapter boundary and surrounding context.
- Promote exact quotations only after checking the source image.
- Move mathematical candidates into canonical equation pages only after formula typography is corrected.
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