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Why output of common emitter amplifier is inverted?
In a common emitter amplifier, the base-emitter current causes a corresponding collector-emitter current, in the ratio of hFe (beta gain) or collector resistance over emitter resistance, which ever is less. Since this ratio is usually greater than one, the differential collector current is greater than the differential base current. This results in amplification of the base signal. As you increase the base-emitter current, the collector-emitter current also increases. This results in the collector being pulled towards the emitter, with the result that the differential collector voltage decreases. This results in inversion of the base signal.
Why is collector current less than emitter current?
The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
Why is collector current slightly less than emitter?
The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
What will happen to voltage divider circuit if emitter resistance is greater than collector resistance?
The gain of a class A, common emitter BJT amplifier, a fairly standard configuration, is defined as collector resistance divided by emitter resistance, or as hFe, whichever is less. Assuming that we are operating in a linear mode, and hFe is not a limiting factor, then the emitter resistance being greater than the collector resistance simply means that the gain is less than one.
Why collector is made larger than base and emitter in a transistor?
Collector has larger area than base and emitter because base collector is reverse biased, hence the current flow here due to the minority carriers and the large power dissipation takes place by the majority carriers, this power dissipated in the form of heat.. To cool the device from heat we made the larger area........
What is the working of a transistor?
For proper working of a transistor,the voltage at the base region must be more positive than that of the emitter region.The voltage at the collector region, in turn, must be more positive than that of the base region.when voltage is applied to transistor, the emitter supplies electron,which is pulled by the base from the emitter as it is more positive than the emitter.This movement of electrons from emitter to collector creates as flow of electricity through the transistor.The current passes from the emitter to the collector through the base.Thus, adjustment of voltage in the base region modifies the flow of the current in the transistor by changing the number of electron in the base region. In this way, small changes in the base voltage can cause large changes in the current flowing out of the collector. We have three transistor element, a.)Emitter b.)Base c.)Collector
Why is common emitter is greater than common collector?
Common-emitter gives more voltage gain because a common-collector amplifier has a voltage gain of 1. But a common-collector can have a power gain because the input impedance is much more than the output impedance.
Why is collector slightly less than emitter?
some of emitter current goes out base instead of collector
Why is collector current increased slowly with the increase of collector to emitter voltage of a common emitter?
The percentage of doping in emitter is higher than collector region.hence large current is flow to emitter than collector.
IS Emitter base resistance greater than emitter collector resistance in transistor?
It depends on whether the transistor is in the active region or not. Usually, the transistor would be in the active region when we are asking this question. if we look at the data sheet for the popular 2N3905 transistor, available at http://www.fairchildsemi.com/ds/2N/2N3905.pdf, we see that if V collector-emitter is 10 V, the collector current is 1 mA, and the small signal frequency is 1 kHz, the typical small signal signal input impedance (which is nearly the same as small signal base-emitter resistance) is about 5,000 ohms. Under the same conditions, the typical output admittance, (which is nearly the same as the small signal collector-emitter resistance) is about 30 microsiemens. Calculate 1/0.000030 to find that this is the same as about 33,000 ohms, so in this case the collector-emitter small signal resistance is greater than the base-emitter small signal resistance. You might be able to find an operating point where the reverse is true.
What are the bias condition of the base emitter and base collector junction for a transistor to operate as a switch?
In order for a transistor to operate as a switch, the base-emitter current must be greater than the collector-emitter current divided by a factor of hFe. In this state, the transistor operates in saturated mode, fully turning on.
What are the bias conditions of the base emitter and base collector junction for a transistor to operate as a switch?
In order for a transistor to operate as a switch, the base-emitter current must be greater than the collector-emitter current divided by a factor of hFe. In this state, the transistor operates in saturated mode, fully turning on.
