1. Satish Pradhan dnayansadhana college, Thane
( Academic Year 2017 – 2018)
SEMESTER SECOND
Subject-Physics
Paper-II
Class- F. Y. B. Sc
TOPIC : NORTAN’S THEOREM
Presented By
Ms. Ankita P. Angre
Department of Physics

2. NORTON’S THEOREM: Assume that the network enclosed below is composed
of independent sources and resistors.
Network
Norton’s Theorem states that this network can be
replaced by a current source shunted by a resistance R.

3. NORTON’S THEOREM: Assume that the network enclosed below is composed
of independent sources and resistors.
Network
Norton’s Theorem states that this network can be
replaced by a current source shunted by a resistance R.

4. NORTON’S THEOREM: We recall the following from source transformations.
In view of the above, if we have the Thevenin equivalent
circuit of a network, we can obtain the Norton equivalent
by using source transformation.
However, this is not how we normally go about finding
the Norton equivalent circuit.

5. NORTON’S THEOREM: Circuit diagram
Find the Norton equivalent circuit to the left of terminals A-B
for the network shown below. Connect the Norton equivalent
circuit to the load and find the current in the 50  resistor.
Circuit diagram

6. NORTON’S THEOREM: Circuit for find INORTON.
It can be shown by standard circuit analysis that

7. NORTON’S THEOREM:
It can also be shown that by deactivating the sources,
We find the resistance looking into terminals A-B is
RN and RTH will always be the same value for a given circuit.
The Norton equivalent circuit tied to the load is shown below.
Final circuit

8. NORTON’S THEOREM: Circuit .
This example illustrates how one might use Norton’s Theorem in electronics.
the following circuit comes close to representing the model of a transistor.
For the circuit shown below, find the Norton equivalent circuit
to the left of terminals A-B.
Circuit .

9. NORTON’S THEOREM: Example 10.7. continued
We first find;
We first find VOS:

10. NORTON’S THEOREM: Example 10.7. continued
Figure 10.34: Circuit for find ISS, Example 10.7.
We note that ISS = - 25IS. Thus,

11. NORTON’S THEOREM: Circuit for find VOS,
From the mesh on the left we have;
From which,

12. NORTON’S THEOREM: We saw earlier that, Therefore;
The Norton equivalent circuit is shown below.
Norton Circuit for Example 10.7

13. Extension of Example Using source transformations we know that the
Thevenin equivalent circuit is as follows: .

14. Questions?

15. THANK YOU