# Circuit Theory

## Reciprocity Theorem

Reciprocity Theorem states that – In any branch of a network or circuit, the current due to a single source of voltage (V) in the network is equal to the current through that branch in which the source was originally placed when the source is again put in the branch in which the current was …

## Norton’s Theorem

Norton’s Theorem states that – A linear active network consisting of the independent or dependent voltage source and current sources and the various circuit elements can be substituted by an equivalent circuit consisting of a current source in parallel with a resistance. The current source being the short-circuited current across the load terminal and the …

## Millman’s Theorem

The Millman’s Theorem states that – when a number of voltage sources (V1, V2, V3……… Vn) are in parallel having internal resistance (R1, R2, R3………….Rn) respectively, the arrangement can replace by a single equivalent voltage source V in series with an equivalent series resistance R.  In other words; it determines the voltage across the parallel branches …

## Compensation Theorem

Compensation Theorem states that in a linear time-invariant network when the resistance (R) of an uncoupled branch, carrying a current (I), is changed by (ΔR), then the currents in all the branches would change and can be obtained by assuming that an ideal voltage source of (VC) has been connected such that VC = I …

## Tellegen’s Theorem

Tellegen’s Theorem states that the summation of power delivered is zero for each branch of any electrical network at any instant of time. It is mainly applicable for designing the filters in signal processing. It is also used in complex operating systems for regulating stability. It is mostly used in the chemical and biological system …

## Superposition Theorem

Superposition theorem states that in any linear, active, bilateral network having more than one source, the response across any element is the sum of the responses obtained from each source considered separately and all other sources are replaced by their internal resistance. The superposition theorem is used to solve the network where two or more …

## Different Methods of Finding Thevenin’s Resistance

Thevenin’s theorem gives the mathematical technique of replacing the given network by a single voltage source by a resistance in series. The different methods of finding Thevenin’s Resistance or internal impedance are as follows: For Independent Sources – The most common method of finding the equivalent Thevenin’s Resistance (RTH) or the internal impedance of any linear, …

## Thevenin’s Theorem

Thevenin’s Theorem states that any complicated network across its load terminals can be substituted by a voltage source with one resistance in series. This theorem helps in the study of the variation of current in a particular branch when the resistance of the branch is varied while the remaining network remains the same. For example …

## Source Transformation

Source Transformation simply means replacing one source by an equivalent source. A practical voltage source can be transformed into an equivalent practical current source and similarly a practical current source into voltage source. Any practical voltage source or simply a voltage source consists of an ideal voltage source in series with an internal resistance or …

## Kirchhoff’s Current Law and Kirchhoff’s Voltage Law

Kirchhoff’s Law: A German physicist Gustav Kirchhoff developed two laws enabling easy analysis of interconnection of any number of circuit elements. The first law deals with the flow of current and is popularly known as Kirchhoff’s Current Law (KCL) while the second one deals with the voltage drop in a closed network and is known …