Thermal noise and Johnson–Nyquist noise theory
E175077
Thermal noise and Johnson–Nyquist noise theory is the foundational framework in electrical engineering and physics that quantifies the random voltage and current fluctuations arising from the thermal agitation of charge carriers in resistive components.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Nyquist noise | 1 |
| Thermal agitation of electric charge in conductors (1928 paper) | 1 |
| Thermal noise and Johnson–Nyquist noise theory canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1523948 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
Target entity: Thermal noise and Johnson–Nyquist noise theory Context triple: [Harry Nyquist, notableWork, Thermal noise and Johnson–Nyquist noise theory]
-
A.
Rayleigh–Jeans law at low frequencies
The Rayleigh–Jeans law at low frequencies is the classical approximation for blackbody radiation that accurately describes the long-wavelength, low-energy limit of Planck’s radiation spectrum.
-
B.
Unruh effect
The Unruh effect is a predicted phenomenon in quantum field theory where an accelerating observer perceives what inertial observers consider vacuum as a warm bath of particles with a characteristic temperature.
-
C.
Theory and Calculation of Alternating Current Phenomena
Theory and Calculation of Alternating Current Phenomena is a foundational electrical engineering text that systematically develops the mathematical analysis and practical design principles of alternating current (AC) circuits and machinery.
-
D.
Onsager reciprocal relations
Onsager reciprocal relations are fundamental symmetry relations in nonequilibrium thermodynamics that link pairs of coupled fluxes and forces, showing that certain transport coefficients are equal.
-
E.
Kirchhoff's law of thermal radiation
Kirchhoff's law of thermal radiation is a fundamental principle in thermodynamics stating that, for a body in thermal equilibrium, its emissivity equals its absorptivity at each wavelength.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: Thermal noise and Johnson–Nyquist noise theory Target entity description: Thermal noise and Johnson–Nyquist noise theory is the foundational framework in electrical engineering and physics that quantifies the random voltage and current fluctuations arising from the thermal agitation of charge carriers in resistive components.
-
A.
Rayleigh–Jeans law at low frequencies
The Rayleigh–Jeans law at low frequencies is the classical approximation for blackbody radiation that accurately describes the long-wavelength, low-energy limit of Planck’s radiation spectrum.
-
B.
Unruh effect
The Unruh effect is a predicted phenomenon in quantum field theory where an accelerating observer perceives what inertial observers consider vacuum as a warm bath of particles with a characteristic temperature.
-
C.
Theory and Calculation of Alternating Current Phenomena
Theory and Calculation of Alternating Current Phenomena is a foundational electrical engineering text that systematically develops the mathematical analysis and practical design principles of alternating current (AC) circuits and machinery.
-
D.
Onsager reciprocal relations
Onsager reciprocal relations are fundamental symmetry relations in nonequilibrium thermodynamics that link pairs of coupled fluxes and forces, showing that certain transport coefficients are equal.
-
E.
Kirchhoff's law of thermal radiation
Kirchhoff's law of thermal radiation is a fundamental principle in thermodynamics stating that, for a body in thermal equilibrium, its emissivity equals its absorptivity at each wavelength.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
noise theory
ⓘ
physical theory ⓘ |
| appliesTo |
conductors in thermal equilibrium
ⓘ
electrical resistors ⓘ resistive components ⓘ |
| assumes |
classical regime where hf << k_B T for white spectrum approximation
ⓘ
thermal equilibrium ⓘ |
| contrastsWith |
flicker noise
ⓘ
shot noise ⓘ |
| dependsOn |
absolute temperature in kelvin
ⓘ
measurement bandwidth in hertz ⓘ resistance value ⓘ |
| describes |
Johnson–Nyquist noise
ⓘ
random current fluctuations in resistors ⓘ random voltage fluctuations in resistors ⓘ thermal noise ⓘ |
| explainsCause | thermal agitation of charge carriers ⓘ |
| field |
electrical engineering
ⓘ
physics ⓘ |
| givesFormula |
i_rms^2 = 4 k_B T B / R
ⓘ
v_rms^2 = 4 k_B T R B ⓘ |
| isIndependentOf |
applied DC voltage
ⓘ
average current through the resistor ⓘ material composition of ideal resistor ⓘ |
| isTypeOf |
equilibrium noise theory
ⓘ
fundamental noise theory in electronics ⓘ |
| noiseSpectralDensityFormula |
S_I(f) = 4 k_B T / R
ⓘ
S_V(f) = 4 k_B T R ⓘ |
| predicts |
frequency-independent noise power spectral density at low frequencies
ⓘ
white noise spectrum over low and moderate frequencies ⓘ |
| relatedTo |
Johnson noise
ⓘ
Nyquist theorem ⓘ fluctuation–dissipation theorem ⓘ white noise ⓘ |
| relatesQuantity |
absolute temperature
ⓘ
electrical resistance ⓘ measurement bandwidth ⓘ noise power ⓘ |
| states |
mean-square noise voltage is proportional to bandwidth
ⓘ
mean-square noise voltage is proportional to resistance ⓘ mean-square noise voltage is proportional to temperature ⓘ |
| symbolForConstant | k_B ⓘ |
| usedIn |
communication system noise analysis
ⓘ
low-noise amplifier design ⓘ noise figure determination ⓘ radio astronomy system design ⓘ receiver sensitivity calculations ⓘ thermal noise limit calculations for sensors ⓘ |
| usesConstant | Boltzmann constant ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Subject: Thermal noise and Johnson–Nyquist noise theory Description of subject: Thermal noise and Johnson–Nyquist noise theory is the foundational framework in electrical engineering and physics that quantifies the random voltage and current fluctuations arising from the thermal agitation of charge carriers in resistive components.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.