Impedance is resistance and reactance ===================================== *Impedance* combines a circuit's resistance (real part) and reactance (imaginary part) into a single complex quantity. The definition applies at a specific angular frequency and is used for steady-state AC analysis. **Notation:** #. :math:`i` is the imaginary unit. **Conditions:** #. Linear, time-invariant circuit operating in steady-state with sinusoidal excitation. #. Resistance and reactance are evaluated at the same angular frequency. **Links:** #. `Wikipedia – Electrical impedance `__ .. py:currentmodule:: symplyphysics.electromagnetism.circuits.alternating_current.impedance.impedance_is_resistance_and_reactance .. py:data:: impedance :attr:`~symplyphysics.symbols.electrodynamics.electrical_impedance` of the system. Symbol: :code:`Z` Latex: :math:`Z` Dimension: :code:`impedance` .. py:data:: resistance :attr:`~symplyphysics.symbols.electrodynamics.electrical_resistance` of the system. Symbol: :code:`R` Latex: :math:`R` Dimension: :code:`impedance` .. py:data:: reactance :attr:`~symplyphysics.symbols.electrodynamics.electrical_reactance` of the system. Symbol: :code:`X` Latex: :math:`X` Dimension: :code:`impedance` .. py:data:: law :code:`Z = R + I * X` Latex: .. math:: Z = R + i X