Ohm's law and its domain
A linear current-voltage relation requires suitable conditions.
Key knowledge
An ohmic element has voltage proportional to current over a stated operating range, V = IR with R constant in that range. This is an empirical material/device relation, not a law satisfied by every circuit element.
Values and equations
V = IR
- V
- Potential difference across the element V
- I
- Current through the element A
- R
- Resistance within the stated linear operating range Ω
Conditions and scope
- Temperature and other relevant physical conditions remain sufficiently fixed.
- Diodes and other nonlinear devices need their own current-voltage characteristics.
Sources · 3
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
- University Physics, volume 2: Ohm's LawSamuel J. Ling, Jeff Sanny and William Moebs / OpenStax, Rice UniversityTextbook chapter
- Ohm's law and drift velocity in conductorsJoe Wolfe / School of Physics, University of New South WalesTeaching resource
- Current Electricity · Physics (2026–27 reprint)National Council of Educational Research and Training (NCERT)Textbook chapter · PDF
Evidence and review
OpenStax 9.4, linear and nonohmic behavior; UNSW field-proportional drift assumption and V/I relation.
2026-10-10 · Macroscopic linear Ohm relation and limits only; no specific resistor value or semiconductor transport theory is certified.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
V=IR with constant R describes an ohmic response over specified conditions.
Temperature change, nonlinear response and directional asymmetry can invalidate a constant-resistance description.
National Council of Educational Research and Training (NCERT)
- Current Electricity · Physics (2026–27 reprint) IndiaEnglish
3.4 Ohm’s law; 3.6 Limitations; 3.7 temperature
- Current Electricity · Physics (2026–27 reprint)
Entry details
Permanent link to this entry ↗- Record identity
- physics-ohms-law
- Revision
- core.1
- Structured reference record
- Essential core · first collection