Question on voltage in a Thevenin equivalent circuit

[influx]

I am trying to refresh my basic electricity knowledge so the questions might be a little stupid lol.

1) Am I correct in saying that the voltage, V1, across the 6 ohm resistor is equal to the V_OC?

2) Why isn't the voltage across the voltage source, V2, equal to V1 and V_OC? I thought that the voltages in a parallel circuit are equal?


Cheers!

 

[gneill]

I am trying to refresh my basic electricity knowledge so the questions might be a little stupid lol.

1) Am I correct in saying that the voltage, V1, across the 6 ohm resistor is equal to the V_OC?

Yes. There's no potential drop across the 5 Ω resistor when terminals a-b are open as shown.

2) Why isn't the voltage across the voltage source, V2, equal to V1 and V_OC? I thought that the voltages in a parallel circuit are equal?

They are not in parallel. There are components in between their respective leads. In particular, the 3 Ω resistor and the controlled voltage source separate the 10 V supply and the 6 Ω resistor's upper leads.

 

[influx]

Yes. There's no potential drop across the 5 Ω resistor when terminals a-b are open as shown.


They are not in parallel. There are components in between their respective leads. In particular, the 3 Ω resistor and the controlled voltage source separate the 10 V supply and the 6 Ω resistor's upper leads.

So if there are components between the wire connecting two elements, the two elements are not in parallel?

Thanks

 

[gneill]

So if there are components between the wire connecting two elements, the two elements are not in parallel?

Thanks

Correct. For two components to be in parallel they must share two nodes.

 

[rezeew]

I am happy to help clarify your understanding of voltage in a Thevenin equivalent circuit.

1) Yes, you are correct in saying that the voltage, V1, across the 6 ohm resistor is equal to the open-circuit voltage (VOC). This is because the Thevenin equivalent circuit is designed to simplify complex circuits into a single voltage source and a single resistor, where the voltage across the resistor (V1) is equal to the voltage of the original circuit when it is open (VOC).

2) While it is true that in a parallel circuit, the voltages across each branch are equal, this is not necessarily the case in a Thevenin equivalent circuit. This is because the Thevenin equivalent circuit is an approximation of the original circuit, and the voltage across the voltage source (V2) is determined by the voltage divider rule, rather than being equal to V1 and VOC. This is due to the presence of the equivalent resistor, which affects the voltage distribution in the circuit.

I hope this helps clarify your understanding of voltage in a Thevenin equivalent circuit. Keep asking questions and learning, there is no such thing as a stupid question in science!