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5. What is Thevenin Theorem? What is Thevenin’s theorem?

# What is Thevenin Theorem? What is Thevenin’s theorem?

Hello friends In this article we will know what is Thevenin’s theorem? And what is its formula? And learn about many facts related to it.

## Thevenin Theorem | Thevenin’s theorem

Fig. 3.8 (f) Enclosed in a box Network In which two terminals A and B are taken out. Any number of resistors and emf sources connected in any way to the network in the box. But according to Thevenin, the entire circuit behind terminals A and B can be replaced with a single source of emf.

ETh ,thevenin voltage ) in series with a single resistance R (called Thevenin resistance) as shown in Fig. 3.8 (i). ETh and RTh The values ​​of k are determined as described in Thevenin’s theorem. Once Thevenin’s equivalent circuit is obtained [देखिए चित्र 3.8 (i)]then any load resistance R connected across ABL Section I is given by-

I = ETh/(RTh + RL,

Thevenin’s theorem as described in D.C. applies to. The circuit is stated below:

Any linear, bilateral network consisting of terminals A and B can be replaced with a single source of emf ETh in series with a single resistance RTh.

• emf ETh is the voltage received across terminals A and B with load, if any is removed i.e. it is the open circuit voltage between terminals A and B.
• Resistance RTh of the network measured between terminals A and B resistance in which the load is removed and the sources of emf are replaced by their internal resistances. Ideal voltage sources are replaced by short circuit and ideal current sources are replaced by open circuit.

Illustration, Consider the circuit shown in Fig. 3.9 (i) As far as the circuit behind the terminals AB is concerned, it is called a single resistance R.Th can be replaced by a single source of emf in series with , as shown in Fig. 3.9 (ii). emf R in terminal ABL is removed with, RL with, is disconnected, R1 There is no current in E, and ETh R3 The voltage seen across will be,

ETh = R3 voltage across

= R3 Current through × Resistance R3

= (V × R3) / (R1 + R3,

RTh To find out, remove the load R, and replace the battery with a short-circuit as its internal resistance is assumed to be zero. Then the resistance measured between A and B is equal to R. Obviously, the terminals AB, R1 and R3 looking back in parallel and this parallel combination R2 is in range with.

RTh = R3 + R1R3 / (R1 + R3,

when load RL is connected between terminals A and B, then RL By whom is the clause given in:-

I = ETh / (RTh + RL,