Norton Theorem

  1. Explain Norton’s Theorem.
  2. Outline the procedure adopted when using Norton’s Theorem.
  3. Determine the short circuit current ISC and the equivalent Resistance RN (parallel)
  4. Construct circuit base on Norton’s Theorem.
  5. Solve linear circuits problem using Norton’s Theorem.

It is possible to reduce a complex circuit to a single current source and parallel resistance connected to a load.

Steps:
  1. Remove the load resistor RL or component concerned and short circuit the terminals. Find IN on the output terminals A and B.
  2. Short-circuit the two voltage sources and open circuit terminals A and B, the two resistors are now connected together in parallel. Find RN.
  3. Having found both the short circuit current, IN and equivalent internal resistance, RN. Draw the Nortons equivalent.
  4. Replace the original load resistor (remove resistor) connected across terminals A and B and calculate current, I.

Solved Example:

9154-01

A two terminal network is connected to a resistive load whose resistance is equal to Norton resistance of the network. What will be the load current if Norton current is I$_n$? (DSSSB JE EE Nov 2019)

Correct Answer: B

Solved Example:

9154-02

When a circuit is represented by equivalent Thevenin's circuit and Norton's circuit: (MPSC Assistant Engineer EE Mains 2019 - Paper I)

Correct Answer: B

Solved Example:

9154-03

Which of the following statements is true for Norton's Theorem? (DFCCIL Executive Electrical Sept 2021)

Correct Answer: D

Solved Example:

9154-04

Norton Theorem states that an entire network connected to a pair of terminals can be replaced with: (URSC (ISRO) Tech Asst (Electronics): August 2017)

Correct Answer: B