- What is the principle of transistor?
- Why are collectors bigger?
- What are three regions in transistor?
- Why is emitter always forward biased?
- Which is the largest of the three transistor currents?
- Why Collector is moderately doped?
- What is the difference between PNP and NPN transistor connections?
- What is leakage current in a transistor?
- Which transistor current is always the largest?
- Why most transistors are NPN type and not PNP type?
- Which region in a transistor is the most heavily doped?
- Which region in a transistor is very thin and lightly doped?
What is the principle of transistor?
For an NPN transistor, it consists of a layer of P-doped semiconductor between two layers of N-doped material, where electrons are passed from the emitter to the collector instead.
The emitter then “emits” electrons into the base, with the base controlling the no.
of electrons the emitter emits..
Why are collectors bigger?
The collector region is the largest of all regions because it must dissipate more heat than the emitter or base regions. It is designed to be large because in order to dissipate all the heater, the extra surface area allows it to do so.
What are three regions in transistor?
A BJT consists of three differently doped semiconductor regions: the emitter region, the base region and the collector region. These regions are, respectively, p type, n type and p type in a PNP transistor, and n type, p type and n type in an NPN transistor.
Why is emitter always forward biased?
As the emitter-base is forward biased the input resistance i.e the resistance of the emitter -base junction becomes very small. Again as the collector base junction is reverse biased the output resistance i.e the resistance of the emitter -collector becomes very high.
Which is the largest of the three transistor currents?
emitter currentWhich is the largest of the three transistor currents? The emitter current is the largest.
Why Collector is moderately doped?
Base is lightly doped because we want that the base current should be small. Now the collector is moderately doped may be because we dont want a crowd of electrons in the collector otherwise the electrons coming from the Emitter-Base path may repelled and collector current may decrease.
What is the difference between PNP and NPN transistor connections?
The main difference between the two types of transistors is that holes are the more important carriers for PNP transistors, whereas electrons are the important carriers for NPN transistors. Then, PNP transistors use a small base current and a negative base voltage to control a much larger emitter-collector current.
What is leakage current in a transistor?
The current in the blocking direction in a diode is called the leakage current. There are no leakage currents in the transistor with its two diodes if one. electrode is open at a time.
Which transistor current is always the largest?
emitter currentThe emitter current is the largest, the collector current is the smallest, and the base and emitter currents are close.
Why most transistors are NPN type and not PNP type?
A NPN transistor has electrons as majority charge carriers whereas the PNP transistor has holes as majority charge carrier. The mobility of electrons is better than mobility of holes. … mobility of electrons is more than hole,so as a result npn transistor are faster than pnp that’s why they are preferred..
Which region in a transistor is the most heavily doped?
emitter regionThe emitter region is the most heavily doped area of the transistor. The emitter contains the largest amount of charge carriers out of all regions in the transistor.
Which region in a transistor is very thin and lightly doped?
The base region of a BJT transistor is very thin and is lightly doped with current carriers. It is the region of a transistor which has opposite polarity charge carriers from the emitter and the collector regions.