@A transistor is a device that regulates current or voltage flow and acts as a switch or gate for electronic signals. @Working of npn transistor @Working of pnp transistor

1. Presentation topic
• n-p-n transistor
• p-n-p transistor and their working principle.

2. What is transistor
A transistor is a device that regulates current or voltage
flow and acts as a switch or gate for electronic signals.
Transistors consist of three layers of a semiconductor
material, each capable of carrying a current.

3. Types of transistor
Accordingly there are two types of transistor
1. n-p-n transistor
2. p-n-p transistor
n-p-n transistor: The npn transistor contains a thin p-region between two n-regions.
P-n-p transistor: The pnp bipolar transistor contains a thin n-region sandwiched
between two p-regions.

4. Introducing of transistor terminal

5. Working of npn transistor
The npn transistor with forward bias to emitter-base junction and reverse
bias to collector-base junction.The forward bias causes the electrons in n-
type emitter to flow towards the base.Only few electrons (less than 5%)
combine with holes to constitute base. More than 95% cross over into the
collector region.

6. Working of pnp transistor
The forward bias causes the holes in the p-type emitter to flow
towards the base. Only few holes less than 5% combine with the
electrons. The remainder more than 95% cross into the collector
region.

7. End of the presentation
Thank You