# PN Junction Question

1. Feb 5, 2015

### CKaiL

1. The problem statement, all variables and given/known data
http://[ATTACH=full]199661[/ATTACH]

[B]2. Relevant equations[/B]

[B]3. The attempt at a solution[/B]

It has becomes a P type semi conductor due to the fact that there is more acceptor than donor. From definition , forward bias is the direction of easy current flow while reverse bias is in the direction of little to no current flow. I check online and it say that when it is in reverse bias , voltage at the cathode (P type junction) is higher but why?

Last edited by a moderator: May 7, 2017
2. Feb 5, 2015

### CWatters

That's down to how diodes work. It's the polarity of the applied voltage that determines if the diode is conducting or not. That should be in your text books. If not try..

3. Feb 6, 2015

### CKaiL

Hi
Could I check with you when it is reverse bias , does the positive side of the battery point to the A and negative point to the B in this question? or another way round?

4. Feb 6, 2015

5. Feb 6, 2015

### rude man

Right.
A reverswe-biased junction has the p side negative and the n side positive.

6. Feb 6, 2015

### CKaiL

One more question from me.
I understand that under reverse bias condition , there is an increase in barrier voltage. But i would like know which terminal has a higher voltage with respect to another ? The one closer to the P junction (point B) or the one closer to N junction (point A)

7. Feb 6, 2015

### TSny

Point A will be at a higher potential compared to point B for reverse bias.