Question

What is a pn junction diode?

Answer 1

A PN junction diode is a basic electronic component made by joining two types of semiconductor materials — P-type and N-type — together.

Let’s break it down simply:

1. P-type semiconductor has more holes (positive charge carriers).
   

1. N-type semiconductor has more electrons (negative charge carriers).
   

When these two are joined together, they form a PN junction. This junction has a special property — it allows current to flow in only one direction.

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Working of a PN junction diode:

1. Forward Bias (ON condition):
   

  - Positive terminal of the battery is connected to the P-side, and negative to the N-side.
  - Current flows easily through the diode.

1. Reverse Bias (OFF condition):
   

  - Positive terminal is connected to the N-side, and negative to the P-side.
  - Current does not flow (except a tiny leakage current).

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Symbol of Diode:

`
       |>|
P-side |  | N-side
       Anode → Cathode
`

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Applications:

1. Used to convert AC to DC (rectifiers).
   

1. Protect circuits from reverse polarity.
   

1. Used in signal demodulation, voltage regulation (Zener diode), etc.
   

Let me know if you want diagrams or real-life examples — happy to help!