Trying to understand how voltage \$ V_{D1} \$ is found.

Here's the original circuit with solution:

enter image description here

Here's how I think it can be redrawn, basically the grounds are just one node:

enter image description here

So to find voltage \$ V_{d1} \$ one first considers what's voltage at point 1, positive side of \$V_{d1}\$ right?

Well, at point 1, voltage is what? \$ -10K \times 1.33mA? \$

How about voltage across 5k resistor? Point 1 is between 10k and 5k resistors...

For point 2 it's 0, since the node of that point is connected to ground, right?

  • \$\begingroup\$ Here's a similar, simpler question, i.imgur.com/yV5EAyX.jpg. Basically, what's the voltage at point 1? Is it: (current through R1) times R1 + (current through R2) times R2??? \$\endgroup\$
    – Jack
    Oct 17, 2017 at 1:52

1 Answer 1


For \$V_{D1}\$ you can consider two KVL loops—they should both give you the same answer.

At point 1, you could start from the leftmost source (start from the ground) and say:

$$ \text{10V}-i_{D2}(10\text{k})-V_{D1}=0$$


simulate this circuit – Schematic created using CircuitLab

You already have the current then solving for \$V_{D1}\$ results in \$V_{D1}=-3.3\text{V}\$

You may also use another KVL loop:


simulate this circuit

$$ V_{D1}-i_{D2}(5\text{k})-(-10\text{V})=0$$

And solving for \$V_{D1}\$ will result in the same.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.