28 July 2019

Difference between resistance and impedance

Definition of resistance and impedance:

Resistance is the opposition to the flow of electric current offered by a substance. It is represented by the R.

Impedance is total opposition to the flow of AC current because of any three components that are resistive, capacitive or inductive. It is represented by Z.

The basic difference between resistance and impedance is explained below keeping in mind the various factors like the basic definition of resistance and impedance, real and imaginary numbers, phase angle, power dissipation, and energy stored. 

The main key difference between resistance and impedance are given below.
  • Resistor occurs in both AC and DC circuit whereas impedance takes place the contribution of both resistance in an AC circuit.
  • Resistance is the contribution of the resistive element in the circuit while the contribution of both resistance and reactance forms impedance.
  • Resistance denoted by R while impedance denoted by Z.
  • The opposition offered to the flow of current in an electric circuit whether AC or DC is known as the resistance, the opposition offered to the flow of current in an AC circuit because of resistance, capacitance and inductance are known as impedance.
  • Impedance has both magnitude and phase angle whereas resistance does not have any phase angle.
  • The resistance of the circuit does not vary according to the frequency of AC or DC whereas impedance varies with the change in frequency.
  • Impedance is subjected to a magnetic field it represents both power dissipation and energy storage while resistance is an electromagnetic field represents power dissipation in any material.
  • Resistance is a simple value consisting of only real number while the impedance of both real and imaginary numbers.
  • Resistance is too much simple while in impedance will consider reactance in addition to resistance to determine it.
  • Impedance may often take into consideration the overall circuit while resistance may or may not.
  • Resistance is pure ohmic impedance.
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