Question

Definition of impedance.

Answer 1

Hint: Impedance is one of the attributes of electronic components that measure resistance or opposition to the alternating current or direct electric current. Impedance could be a vector quantity that consists of two independent one-dimensional phenomena such as resistance and reactance.

Complete step-by-step solution:
Impedance could be a kind of resistance or opposition to the flow of AC current due to any three components that are resistive, inductive, or capacitive. It’s a mixture of both resistance and reactance within a circuit. Resistance is simply termed as the opposition to the flow of electric current within the circuit. Resistance will be seen in both AC and DC circuits. Impedance will be seen only in AC circuits. Resistance is caused due to the electrons in a conductor colliding with the ionic lattice of the conductor which ends within the conversion of electrical energy in heat. It might be said that electrical resistance is the opposition to steady electric current. When connected with DC, an ideal resistance does change with frequency. Impedance is the measure of the character of the opposition of the AC electricity which is created because of inductance and capacitance. This opposition varies with the frequency. Very often, reactance and impedance are thought to be identical and are interchangeably used. It’s important to understand that reactance is the resistance offered to the AC current by inductors and capacitors only while impedance is the sum of the resistance and reactance.
Dimension: It’s an expression that relates derived quantity to fundamental quantities. The elemental dimensions utilized in mechanics are time, mass, and length. Symbolically, these are written as \[t,m\] and \[l\], respectively. The study of electromagnetism adds a further fundamental dimension, electric charge. Other quantities have dimensions compounded of those.
- Unit of impedance is ohm and
- Dimension of Impedance \[ = \dfrac{V}{I} = \dfrac{W}{{QI}}\]
\[ = \dfrac{{\left[ {M{L^2}{T^{ - 2}}} \right]}}{{\left[ {QQ{T^{ - 1}}} \right]}}\] Where dimension of \[W = \left[ {M{L^2}{T^{ - 2}}} \right]\] and \[I = \left[ {Q{T^{ - 1}}} \right]\]
\[ = \left[ {M{L^2}{T^{ - 1}}{Q^{ - 2}}} \right]\]

Note: Convert the impedance equation in terms of charge, \[Q\]. You must know the definition of voltage. You must know the definition of impedance. Attempt to make the equation in terms of \[Q\] before going for dimension. Make sure of signs while going to the numerator. Try and memorize the basic dimensions.