Question

“Any two-terminal active circuit containing voltage sources and resistances, when viewed from its output terminals, is equivalent to a constant current source and an internal resistance.” This represents:

• A. Maximum power transfer theorem
• B. Superposition theorem
• C. Norton’s theorem
• D. Thevenin’s theorem

Hint:

Norton’s equivalent: current source + parallel resistance. Thevenin’s equivalent: voltage source + series resistance.

Answer 1

The Correct Option is C

Norton's Theorem is the principle that states any two-terminal active circuit containing voltage sources and resistances, when viewed from its output terminals, is equivalent to a constant current source in parallel with an internal resistance. This theorem simplifies the analysis of complex circuits and is particularly useful for analyzing power systems and electronic circuits. By using Norton's Theorem, complex networks can be reduced to a simple equivalent circuit which makes calculations more straightforward and less prone to error. The key steps to apply Norton's Theorem are as follows:

1. Identify the portion of the circuit to be analyzed: Remove the load resistor from the original circuit if present.
2. Calculate the Norton equivalent current (I_N): Find the short-circuit current across the output terminals (where the load was connected).
3. Determine the Norton equivalent resistance (R_N): Turn off all independent voltage and current sources (replace voltage sources with short circuits and current sources with open circuits) and calculate the resistance between the open terminals where the load was originally connected.
4. Construct the Norton equivalent circuit: Place the calculated I_N in parallel with R_N at the terminals where the load is connected.

This simplification technique that converts a network of sources and resistors into a simple equivalent circuit is what makes Norton's Theorem powerful for analysis and solution of complex electrical circuits.