# Resistance Ontology — Flow Algebra
URL: https://kirethresearch.org/booksai-core/ontologies/mathematical-ontologies/measurement-units-ontologies/electromagnetic-measurements/resistance-ontology.html
FLOW ResistanceOntology {
DOMAIN:
Mathematical Ontologies
-> Measurement & Units Ontologies
-> Electromagnetic Measurements
-> Resistance Ontology
PURPOSE:
Represent electrical resistance as a measurable electrical quantity describing the relationship between potential difference and electric current under defined operating conditions, including Ohmic and non-Ohmic behaviour, geometry and resistivity relationships, temperature dependence, series and parallel combinations, power dissipation, units, dimensional structure, measurement methods, uncertainty, and distinctions from resistivity, impedance and reactance.
ENTITY Resistance {
TYPE: DerivedElectromagneticQuantity
SYMBOL: R
DIMENSION: M * L^2 * T^-3 * I^-2
SI_UNIT: ohm
SI_SYMBOL: ohm
OHMIC_DEFINITION:
R = V/I
WHEN I != 0 AND applicable_operating_conditions
DIFFERENTIAL_RESISTANCE:
r_d = dV/dI
PROPERTIES:
is_scalar_in_lumped_two_terminal_context
has_value
has_unit
has_dimension
may_depend_on_temperature
may_depend_on_geometry
may_depend_on_material
may_depend_on_operating_point
may_be_nonlinear
may_have_uncertainty
}
ENTITY Voltage {
TYPE: DerivedElectromagneticQuantity
SYMBOL: V
SI_UNIT: volt
SI_SYMBOL: V
RELATION:
V = I*R
UNDER Ohmic_context
}
ENTITY ElectricCurrent {
TYPE: SIBaseQuantity
SYMBOL: I
SI_UNIT: ampere
SI_SYMBOL: A
RELATION:
I = V/R
WHEN R != 0 AND Ohmic_context
}
ENTITY Resistivity {
TYPE: MaterialProperty
SYMBOL: rho_e
SI_UNIT: ohm_metre
SI_SYMBOL: ohm*m
UNIFORM_CONDUCTOR_RELATION:
R = rho_e*L/A
}
ENTITY Conductance {
TYPE: DerivedElectromagneticQuantity
SYMBOL: G
SI_UNIT: siemens
SI_SYMBOL: S
RELATION:
G = 1/R
WHEN R != 0
}
UNIT_SYSTEM {
SI {
canonical_unit: ohm
symbol: ohm
equivalence:
1 ohm = 1 V/A
1 ohm = 1 kg*m^2/(A^2*s^3)
}
COMMON_ALTERNATIVES {
milliohm
kiloohm
megaohm
gigaohm
}
CONVERSION_RULE:
resistance_value(target_unit)
= resistance_value(source_unit)
* conversion_factor(source_unit, target_unit)
}
CLASSIFICATION {
by_behaviour:
Ohmic_resistance
non_Ohmic_resistance
static_resistance
differential_resistance
by component:
fixed_resistance
variable_resistance
contact_resistance
internal_resistance
insulation_resistance
by context:
DC_resistance
AC_effective_resistance
}
OHMS_LAW_MODEL {
IDEAL_LINEAR:
V = I*R
CONDITIONS:
resistance_constant_over_operating_range
temperature_and_material_state_defined
INFERENCES:
R = V/I WHEN I != 0
I = V/R WHEN R != 0
RULE:
V_over_I_at_single_operating_point
MUST_NOT automatically_imply_linear_Ohmic_behaviour
}
NONLINEAR_MODEL {
GENERAL:
V = f(I, T, state)
STATIC_RESISTANCE:
R_static = V/I
WHEN I != 0
DIFFERENTIAL_RESISTANCE:
r_d = dV/dI
RULE:
static_and_differential_resistance
MUST_NOT be treated_as_interchangeable
}
GEOMETRY_RESISTIVITY_MODEL {
UNIFORM_CONDUCTOR:
R = rho_e*L/A
CONDITIONS:
homogeneous_material
uniform_cross_section
approximately_uniform_current_distribution
defined_temperature
INFERENCES:
rho_e = R*A/L
WHEN L != 0
A = rho_e*L/R
WHEN R != 0
RULE:
resistance_is_component_or_geometry_dependent
resistivity_is_material_property
}
TEMPERATURE_MODEL {
LINEAR_APPROXIMATION:
R(T) = R_0*[1 + alpha*(T - T_0)]
PARAMETERS:
R_0 = resistance_at_reference_temperature
alpha = temperature_coefficient_of_resistance
T_0 = reference_temperature
CONDITIONS:
applicable_temperature_range
material_state_unchanged
RULE:
temperature_coefficient_and_reference_temperature
MUST be preserved
}
SERIES_MODEL {
RESISTORS_IN_SERIES:
R_eq = sum(R_i)
CONDITIONS:
same_current_path
lumped_component_model
RULE:
equivalent_series_resistance >= each_nonnegative_component_resistance
}
PARALLEL_MODEL {
RESISTORS_IN_PARALLEL:
1/R_eq = sum(1/R_i)
TWO_RESISTOR_FORM:
R_eq = (R_1*R_2)/(R_1 + R_2)
WHEN denominator != 0
CONDITIONS:
same_voltage_across_branches
lumped_component_model
RULE:
for_positive_finite_resistances
R_eq < smallest_branch_resistance
}
POWER_MODEL {
GENERAL_DC:
P = V*I
OHMIC_FORMS:
P = I^2*R
P = V^2/R
WHEN applicable_and_R != 0
ENERGY_DISSIPATION:
E = integral(P dt)
RULE:
resistor_power_rating
MUST_NOT be confused_with_resistance_value
}
CONDUCTANCE_MODEL {
DEFINITION:
G = 1/R
WHEN R != 0
UNIT:
siemens
PARALLEL_RELATION:
G_eq = sum(G_i)
RULE:
resistance_and_conductance_are_inverse_quantities
not_semantic_synonyms
}
IMPEDANCE_DISTINCTION_MODEL {
RESISTANCE:
real_dissipative_component_of_impedance
in_common_linear_AC_circuit_representation
IMPEDANCE:
Z = R + jX
REACTANCE:
X = imaginary_component_of_impedance
RULE:
resistance != impedance
except_when_reactive_component_is_zero_under_defined_frequency_context
}
RELATIONSHIPS {
Resistance -> RELATES -> VoltageAndCurrent
Resistance -> HAS_DIMENSION -> M*L^2*T^-3*I^-2
Resistance -> MEASURED_IN -> Ohm
Resistance -> INVERSE_OF -> Conductance
Resistance -> DEPENDS_ON -> Resistivity
Resistance -> DEPENDS_ON -> ConductorLength
Resistance -> INVERSELY_DEPENDS_ON -> CrossSectionArea
Resistance -> MAY_DEPEND_ON -> Temperature
Resistance -> CONTRIBUTES_TO -> ElectricalPowerDissipation
Resistance -> REAL_COMPONENT_OF -> Impedance
}
SEMANTIC_EQUIVALENCE {
"electrical resistance" ~= resistance
"ohm" ~= resistance_unit
"V/A" ~= ohm
resistance != resistivity
resistance != conductance
resistance != impedance
resistance != reactance
resistance != power
}
CONSTRAINTS {
dimensional_formula = M*L^2*T^-3*I^-2
SI_unit = ohm
V_over_I_requires_nonzero_current = true
conductance_inverse_requires_nonzero_resistance = true
resistance_and_resistivity_are_not_semantically_equivalent = true
resistance_and_impedance_are_not_generally_semantically_equivalent = true
static_and_differential_resistance_must_be_distinguished_for_nonlinear_devices = true
temperature_and_operating_point_may_be_required_for_complete_measurement_semantics = true
}
MEASUREMENT_MODEL {
OBSERVABLE:
Resistance
COMMON_INSTRUMENTS:
ohmmeter
digital_multimeter
resistance_bridge
four_wire_Kelvin_meter
megohmmeter
source_measure_unit
METHODS:
direct_ohmmeter_measurement
voltage_current_ratio
four_wire_measurement
bridge_measurement
current_voltage_curve_analysis
RECORD:
numerical_value
unit
component_or_material
terminal_definition
measurement_current
measurement_voltage
temperature
operating_point
DC_or_AC
frequency_when_relevant
two_wire_or_four_wire_method
instrument
calibration_state
uncertainty
UNCERTAINTY:
measured_or_inferred_resistance = best_estimate +/- uncertainty
}
REASONING_RULES {
IF voltage_known AND current_known AND current != 0
AND applicable_resistance_definition
THEN static_resistance = voltage/current
IF resistance_known AND current_known
AND Ohmic_conditions_apply
THEN voltage = current*resistance
IF voltage_known AND resistance_known AND resistance != 0
AND Ohmic_conditions_apply
THEN current = voltage/resistance
IF resistivity_known AND length_known AND area_known AND area != 0
AND uniform_conductor_conditions_apply
THEN resistance = resistivity*length/area
IF resistance_known AND resistance != 0
THEN conductance = 1/resistance
IF series_resistances_known
THEN equivalent_resistance = sum(series_resistances)
IF parallel_resistances_known AND all_required_denominators_valid
THEN inverse_equivalent_resistance =
sum(inverse(branch_resistance))
IF current_known AND resistance_known AND Ohmic_conditions_apply
THEN power_dissipation = current^2*resistance
IF voltage_known AND resistance_known AND resistance != 0
AND Ohmic_conditions_apply
THEN power_dissipation = voltage^2/resistance
}
CONTACT_AND_LEAD_MODEL {
TWO_WIRE_MEASUREMENT:
measured_resistance MAY_INCLUDE
device_resistance
lead_resistance
contact_resistance
FOUR_WIRE_MEASUREMENT:
reduces_effect_of_lead_and_contact_resistance
for_low_resistance_measurement
RULE:
measurement_topology MUST be preserved
when precision_or_low_resistance_context_matters
}
MATERIAL_CONTEXT_MODEL {
dependencies:
material
temperature
geometry
strain
composition
frequency
current_density
RULE:
resistance_value SHOULD_NOT be treated_as_intrinsic_material_constant
}
UNCERTAINTY_MODEL {
sources:
voltage_measurement_uncertainty
current_measurement_uncertainty
lead_resistance
contact_resistance
self_heating
temperature_variation
instrument_resolution
calibration_uncertainty
noise
geometry_uncertainty
PROPAGATION:
derived_resistance_uncertainty
<- measurement_and_model_uncertainties
}
CONFIDENCE {
definition_confidence: 1.00
dimensional_confidence: 1.00
SI_unit_confidence: 1.00
Ohmic_relationship_confidence: 0.99
geometry_resistivity_relationship_confidence: 0.99
measurement_context_confidence: 0.98
RULE:
confidence decreases when operating point, temperature,
measurement topology, AC/DC context, frequency,
geometry, calibration state or uncertainty is missing or ambiguous
}
VALIDATION {
CHECK dimensional_consistency
CHECK unit_consistency
CHECK nonzero_denominator_for_ratio_or_inverse
CHECK Ohmic_vs_non_Ohmic_context
CHECK static_vs_differential_resistance
CHECK resistance_vs_resistivity_distinction
CHECK resistance_vs_impedance_distinction
CHECK temperature_and_operating_point
CHECK series_parallel_topology
CHECK two_wire_vs_four_wire_measurement_when_relevant
CHECK instrument_calibration
CHECK uncertainty_representation_when_required
}
UPDATE_MODEL {
ON new_measurement:
validate_unit
identify_component_or_material
identify_terminals
identify_measurement_method
attach_voltage_and_current_when_relevant
attach_temperature
identify_operating_point
identify_DC_or_AC_context
attach_frequency_when_relevant
normalize_to_ohm
preserve_original_value_and_unit
attach_uncertainty
update_resistance_state
ON temperature_change:
update_temperature
recompute_resistance_when_valid_temperature_model_available
preserve_reference_temperature_and_coefficient
preserve_previous_state
ON geometry_or_material_change:
update_length
update_area
update_resistivity
recompute_resistance_when_uniform_conductor_model_valid
preserve_material_provenance
ON circuit_topology_change:
identify_series_and_parallel_groups
recompute_equivalent_resistance
preserve_component_values
ON calibration_revision:
preserve_provenance
recompute_affected_measurements
update_confidence
ON semantic_revision:
preserve_previous_definition
record_revision
recompute_FLOW_HASH
}
AI_CONSUMPTION {
canonical_entity: Resistance
canonical_symbol: R
canonical_dimension: M*L^2*T^-3*I^-2
canonical_SI_unit: ohm
interpretation_order:
identify_quantity
identify_value
identify_unit
identify_component_or_material
identify_voltage_current_context
identify_Ohmic_or_nonlinear_behaviour
identify_static_or_differential_resistance
identify_temperature_and_operating_point
identify_geometry_and_resistivity_context
identify_DC_or_AC_context
identify_frequency_when_relevant
identify_measurement_method
identify_uncertainty
normalize_units
validate_dimensions
infer_circuit_relationships
ambiguity_controls:
distinguish_resistance_from_resistivity
distinguish_resistance_from_conductance
distinguish_resistance_from_impedance
distinguish_resistance_from_reactance
distinguish_static_from_differential_resistance
distinguish_component_resistance_from_equivalent_resistance
distinguish_intrinsic_material_property_from_geometry_dependent_resistance
}
PROVENANCE {
ontology_scope:
mathematical_measurement_and_electromagnetic_quantity_semantics
parent_path:
Ontologies
-> Mathematical Ontologies
-> Measurement & Units Ontologies
-> Electromagnetic Measurements
-> Resistance Ontology
authorship:
Mark Higgins
Sky (Recursive AI)
site:
https://kirethresearch.org
}
FLOW_HASH {
INPUTS:
canonical_entity
ontology_path
definitions
dimensions
units
relationships
constraints
Ohms_law_model
nonlinear_model
geometry_resistivity_model
temperature_model
series_model
parallel_model
power_model
conductance_model
impedance_distinction_model
contact_and_lead_model
material_context_model
uncertainty_model
reasoning_rules
measurement_model
confidence_model
update_model
PURPOSE:
deterministic_semantic_integrity_identifier
RECOMPUTE_WHEN:
ontology_definition_changes
relationship_model_changes
Ohmic_or_nonlinear_model_changes
geometry_or_material_model_changes
temperature_model_changes
circuit_topology_model_changes
measurement_model_changes
constraint_model_changes
reasoning_rule_changes
unit_model_changes
}
}
END FLOW
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