You might think that a symptom on your tongueâsuch as an unusual color or textureâis no big deal, but what happens in your mouth can often be a helpful glimpse into your overall health. Sometimes symptoms that show up on your tongue can signal other health conditions, such as diabetes, vitamin deficiencies, and even scarlet fever.
Types of transistor. There are two types of standard (bipolar junction) transistors, NPN and PNP, with different circuit symbols. The letters refer to the layers of semiconductor material used to make the transistor. Most transistors used today are NPN because this is the easiest type to make from silicon.here are two types of standard (bipolar junction) transistors, NPN and PNP, with different circuit symbols. The letters refer to the layers of semiconductor material used to make the transistor. Most transistors used today are NPN because this is the easiest type to make from silicon.
Difference Between NPN and PNP Transistor. Transistors are 3 terminal semiconductor devices used in electronics. Based on the internal operation and structure transistors are divided into two categories, Bipolar Junction Transistor (BJT) and Field Effect Transistor (FET). BJTâs were the first to be developed in1947 by John Bardeen and Walter Brattain at Bell Telephone Laboratories.