01․ Who invented the first junction transistor?
It was invented by William Shockley at Bell Labs on June 23, 1948 (patent filed June 26, 1948).
02․ The barrier potential across each silicon depletion layer is
For silicon depletion layer, the barrier potential is 0.7 Volts. For germanium depletion layer, the barrier potential is 0.3 Volts.
03․ In an NPN transistor, the majority carriers in the emitter are
In an NPN transistor, the majority current carriers are electrons. In a PNP transistor, the majority current carriers are holes.
04․ The emitter diode is usually
In typical operation, the base emitter junction is forward biased, which means that the P-doped side of the junction is connected with positive potential and the n-doped side of the junction is connected with negative potential. Hence, the base emitter junction acts as a diode in forward bias and that is why it is called as emitter diode.
05․ For normal operation of the transistor, the collector diode has to be
In typical operation, the base collector junction is forward biased, which means that the p-doped side of the junction is connected with negative potential and the n-doped side of the junction is connected with positive potential. Hence, the base collector junction acts as a diode in reverse bias and that is why it is called as collector diode.
06․ The base of an npn transistor is thin and
In a NPN transistor, the base and collectors are lightly doped because it should accept those charge carriers.
07․ Most of the electrons in the base of an NPN transistor flow
In an NPN transistor, few electrons are injected by the emitter into the base of the transistor and few electrons are entering the base flow directly through the base to the positive battery terminal. Most of the emitter current of electrons diffuses through the thin base into the collector. Moreover, the small base current produces a larger change in collector current.
08․ Most of the electrons in the base of an NPN transistor do not recombine because they
Current gain is directly proportional to the recombination lifetime of the electrons in the base and inversely proportional to the base width. In an NPN transistor, the current gain of the electrons in the base is very high. Hence, it has a long lifetime.
09․ The β of a transistor is the ratio of the
The common emitter current gain is represented by beta (β). It is approximately the ratio of the DC collector current to the DC base current in the forward active region.
10․ Increasing the collector supply voltage will increase
By increasing the collector voltage, the load can get the increased voltage at the output side. It does not disturb any of the above mentioned currents.
<<<2627282930>>>
