What is the unit of impedance?

Impedance is the measure of the total opposition that a circuit presents to alternating current (AC). It is a comprehensive value that combines both standard DC resistance and AC reactance (the opposition caused by inductors and capacitors). Because impedance represents an opposition to current flow exactly like basic resistance does, it is measured in the very same unit: the Ohm. The other choices are incorrect because Volts measure electrical potential, Amperes measure current, and Coulombs measure charge.