14 Difference Between Resistance and Impedance

In an earlier tutorials, we have learned the two main differences like-

• Resistance vs Reactance
• Resistance vs Reluctance

In this post, we are going to study what is difference between resistance and impedance.

Resistance vs Impedance in Tubular Form

#	Content	Resistance	Impedance
01	[Definition] What is Resistance & Impedance?	The property of the substance that opposes the flow or limits the current in an electrical DC circuit is known as Resistance.	The property of the substance that opposes the flow and limits the current in an electrical AC circuit is known as Impedance.
02	Symbol of resistance & Impedance	Resistance is represented by the ‘R’.	Impedance is represented by the ‘Z’.
03	Useful quantities	Resistance depends upon the conductor’s dimension, resistivity, temperature.	Reactance depends upon the frequency of the alternating current.
04	Useful element	It consists of only resistive elements (R).	It consists of resistance (R) and reactance (X).
05	Current Functions	Resistance is applicable for DC circuit.	Impedance is applicable for AC circuit.
06	Phase angle	Resistance has the same phase. It means that phase angle does not occur in the resistive circuit.	Impedance has a phase angle.
07	Real & Complex number	It has only real value.	It has a complex (i.e. real and imaginary) value.
08	Electric Power	Due to the resistance, active power is consumed in the electrical circuit.	Due to the impedance, active and reactive power are consumed in the electrical circuit.
09	Effect of Frequency	In an electrical circuit, resistance is constant due to the zero frequency of DC current.	In an electrical circuit, the impedance varies according to the frequency of the AC current.
10	Effect of Power	According to this property, the electrical power is dissipated in the form of heat.	In this property, the electrical power is dissipated and stored.
11	Mesuring Instrument	Resistance is measured by the ohmmeter.	Impedance is measured by the impedance analyzer.
12	Useful function of resistance & impedance	It is useful to find out how much a circuit resists the flow of DC current.	It is useful to find out how much a circuit resists the flow of AC current including the AC reactance and DC resistance.

13. Symbollc representation of Resistance and Impedance

• Resistance (R) Symbol:

• Impedance (Z) Symbol:

14. Formula of Resistance and Impedance

• Resistance Formula

Resistance (R)  = (Voltage / Current)                        (Unit- Ohm)   

Check Online Tool for Calculating Resistance.

• Impedance Formula

Impedance (Z) = [√(R2 + X2)] = [√R2 + (XL-XC)2]        (Unit- Ohm)   

Where, XL is inductive impedance and XC is capacitive impedance.

These are the 14 basic points of comparisons between resistance and impedance with the help of basic concepts, symbolic representation, and their formula.

The similarity in between the resistance and impedance is a unit. Both has same unit i.e. Ohm (Ω)

If you have any queries about the relation between the resistance and impedance, you can hit the comment below.

Other realted Comparison:

• Alternating Current vs Direct Current
• Active Power vs Reactive Power
• Inductor vs Capacitor
• Electrical Circuit vs Magnetic Circuit
• Series Circuit vs Parallel Circuit
• Analog Multimeter vs Digital Multimeter
• Single Phase AC System vs Three Phase AC System

Thanks for Reading!