Which sequence correctly describes how to construct the Thevenin equivalent of a linear network as seen from two terminals?

Which sequence correctly describes how to construct the Thevenin equivalent of a linear network as seen from two terminals?

• A. Find Vth with independent sources active using open-circuit across terminals, find Rth with sources deactivated, then connect Vth in series with Rth.
• B. Short all sources, measure equivalent current.
• C. Replace network with a single resistor equal to Rth.
• D. Replace network with a current source only.

Answer: (A)

The concept being tested is how to form the Thevenin equivalent of a linear network from two terminals. To do this, you first determine the Thevenin voltage by measuring the open-circuit voltage across the terminals with all independent sources active. This open-circuit voltage becomes Vth. Next, you determine the Thevenin resistance by deactivating all independent sources (voltage sources replaced by shorts, current sources opened) and measuring the resistance seen from the terminals; this is Rth. With Vth in series with Rth, you have a Thevenin equivalent that reproduces the same terminal behavior for any load. This works because the open-circuit voltage fixes the voltage source value, and the resistance seen with sources deactivated fixes the series resistance that governs how the network responds to load. Short explanations that replace the network with just a resistor or with a current source omit essential parts of the model and won’t reproduce the correct voltage-current behavior for arbitrary loads.

The concept being tested is how to form the Thevenin equivalent of a linear network from two terminals. To do this, you first determine the Thevenin voltage by measuring the open-circuit voltage across the terminals with all independent sources active. This open-circuit voltage becomes Vth. Next, you determine the Thevenin resistance by deactivating all independent sources (voltage sources replaced by shorts, current sources opened) and measuring the resistance seen from the terminals; this is Rth. With Vth in series with Rth, you have a Thevenin equivalent that reproduces the same terminal behavior for any load. This works because the open-circuit voltage fixes the voltage source value, and the resistance seen with sources deactivated fixes the series resistance that governs how the network responds to load. Short explanations that replace the network with just a resistor or with a current source omit essential parts of the model and won’t reproduce the correct voltage-current behavior for arbitrary loads.