How to find the total resistance of the following circuit
circuit analysisresistors
I tried finding the total resistance but my answer isn't correct. The answer is supposed to be 6.66 kΩ.
Best Answer
In this case whenever you are calculating the circuit resistance you want the total resistance seen by your only voltage source (18 V battery)
you better start from the node C,
Such that i can see a 1 KΩ series with another 1 KΩ
The equivalent resistance of this combination is a 2 KΩ resistance
so your circuit now looks like this
i can see now a 2.2 KΩ (Node B) parallel to a 2 KΩ (Node C)
We can now simply estimate the equivalent resistance of this combination which should be equals to
Now we place this resistance at node (B) and remove the node (C) branch (Open circuit) or vice verse
Such that your new circuit will look like this
Now i can see a 22/21 KΩ Series with a 1 KΩ resistance
Such that they are combined into a new resistance of value 43/21 KΩ
Your circuit will look something like this
Now this circuit can be easily solved
you have a 43/21 KΩ parallel with a 2.2 KΩ
and this whole combination equivalent resistance is series with the 5.6 KΩ resistance
If you're looking for Rth, you do exactly as you said (remove RL such that there is an open-circuit between A and B, then shut V2 off and measure equivalent resistance from A to B).
First, remove the resistor and short V2. If you label nodes at this point, it will help you to redraw the circuit in a more typical fashion:
Convince yourself that that is true, and from there you should be golden :)
the book is pretty correct as the circuit is like this:
simulate this circuit – Schematic created using CircuitLab
This circuit would be in series if there were no wires shorting the circuit and then net resistance would be 15 ohm.
Best Answer
In this case whenever you are calculating the circuit resistance you want the total resistance seen by your only voltage source (18 V battery)
you better start from the node C, Such that i can see a 1 KΩ series with another 1 KΩ
The equivalent resistance of this combination is a 2 KΩ resistance so your circuit now looks like this
i can see now a 2.2 KΩ (Node B) parallel to a 2 KΩ (Node C)
We can now simply estimate the equivalent resistance of this combination which should be equals to
Now we place this resistance at node (B) and remove the node (C) branch (Open circuit) or vice verse
Such that your new circuit will look like this
Now i can see a 22/21 KΩ Series with a 1 KΩ resistance
Such that they are combined into a new resistance of value 43/21 KΩ
Your circuit will look something like this
Now this circuit can be easily solved you have a 43/21 KΩ parallel with a 2.2 KΩ
and this whole combination equivalent resistance is series with the 5.6 KΩ resistance