# Rather simple diode problem

• Learnphysics

## Homework Statement

[PLAIN]http://img27.imageshack.us/img27/4475/q12r.png [Broken]

## Homework Equations

KCL/KVL

Mesh current, node voltage

ohm's law

## The Attempt at a Solution

for b)
I understand how diodes work, and i'v deduced that diode 2 is definitely not conducting as the voltage on it's anode is 0, and the voltage on it's cathode MUST be higher than 0.

To find weather diode 1 is off or not, i need to figure out the voltage at the node where the 12v and 16v lines meet. I tried using KVL, however the path to the 12 volt source has no resistance, and therefore results in me dividing by 0.

KCL can't be used as there's no useful closed loops in this.

Could anyone give me an idea on how to determine the voltage at that node?

I have similar problems with part a), I need to find the voltage of the node on the left, but one of it's arms have no resistance so i can't use node voltage or KCL. there is really not loops to use KVL.

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