High School Forward Biased Diode: Potential Rise vs Battery

[Hydrous Caperilla]

If a diode is connected with P junction with higher voltage and N with low voltage then why is there a potential rise as opposed to the decrease in potential like in battery?

 

[sophiecentaur]

If a diode is connected with P junction with higher voltage and N with low voltage then why is there a potential rise as opposed to the decrease in potential like in battery?

Perhaps you should draw a diagram of this. It doesn't make sense, the way you have stated it.

 

[Hydrous Caperilla]

@sophiecentaur edited

 

[sophiecentaur]

I'm still not sure what you are asking but the characteristic curve https://www.electronics-tutorials.ws/diode/diode_3.htmlshows how an externally applied PD across a diode will affect the current through it.
Your two diagrams are showing two different applied PDs. Are you asking about the fundamental difference between a diode and a battery?
A diode is not a source of Power so there is no emf generated in it. A battery, otoh, is a power source and there is an emf generated along with some losses which can often be described in terms of an internal resistance.

 

[berkeman]

@sophiecentaur edited

The direction of the current shown in your case (b) of forward bias is backwards. The current flows from p to n when forward biased. You can see this from the Diode Equation:

https://en.wikipedia.org/wiki/Shockley_diode_equation

http://www.nptel.ac.in/courses/117107095/lecturers/lecture_2/images/fig1.jpg

 

[sophiecentaur]

The direction of the current shown in your case (b) of forward bias is backwards.

But it looks to me that the battery is connected the same way in both cases. The only difference is the battery volts. But his arrows seem to be showing the direction of electron flow, which is not helping.
I think it really would be better if he started again with a good source about diodes. He just seems a bit muddled.

 

[berkeman]

his arrows seem to be showing the direction of electron flow, which is not helping.

Oh, that's confusing. He should show current direction, IMO.