Difference Between Equivalent Resistance and Effective Resistance

Equivalent Resistance vs Effective Resistance
 

Resistance is a very important property of electrical and electronic circuits. The concept of resistance plays a vital role in fields such as electrical engineering, electronic engineering and physics. It is vital to have a clear understanding of resistance and related subjects in order to be successful in such fields. In this article, we are going to discuss what equivalent resistance and effective resistance are, their definitions, the applications of equivalent resistance and effective resistance, the similarities between these two, and finally the difference between equivalent resistance and effective resistance.

What is Equivalent Resistance?

In order to understand the concept of equivalent resistance, one must first understand the concept of resistance. The resistance, in a qualitative definition, tells us how hard it is for an electrical current to flow. In the quantitative sense, the resistance between two points can be defined as the voltage difference that is required to take a unit current across the defined two points. Electrical resistance is the inverse of electrical conduction. The resistance of an object is defined as the ratio of the voltage across the object to the current flowing through it. The resistance in a conductor depends on the amount of free electrons in the medium. The resistance of a semiconductor mostly depends on the number of doping atoms used (impurity concentration). The resistance a system shows to an alternating current is different from that to a direct current. Therefore, the term impedance is introduced in order to make AC resistance calculations much easier. . The Ohm’s law is the single most important law when the topic resistance is discussed. It states that for a given temperature, the ratio of voltage across two points, to the current passing through those points is constant. This constant is known as the resistance between those two points. The resistance is measured in Ohms. The equivalent resistance of a system is the value of the single resistor that can be used instead of a combination of resistors. For a serial connection of resistors, the equivalent resistance is simply the addition of the resistors. For a parallel configuration, the equivalent resistance R can be obtained from 1/R = 1/R₁ + 1/R₂ +1/R₃ ……

What is Effective Resistance?

Effective resistance is another name given to the term impedance. Effective resistance is defined as the resistance to an alternating current, expressed as the ratio of the power dissipated to the square of the effective current. Effective resistance varies with the frequency of the signal. For passive devices such as resistors, the effective resistance is always a constant. For active devices such as inductors and capacitors, the effective resistance is a function of the frequency.