## What is bjt history, symbol, working and applications (updated) gas national average

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The low signal is applied in the input of Base-Emitter region and output is taken across the load collector resistance connected in the collector circuit. In order to achieve good amplification, the input Base-Emitter circuit should always remain forward biased. electricity voltage in paris To do so, an external D.C voltage (VEE) is applied in the Base-Emitter circuit in addition to the signal as shown given below.

This D.C voltage VEE is known as the bias voltage and its magnitude is such that it always keeps the input B-E circuit forward biased. v gashi 2013 As the input B-E circuit has low resistance, therefore, a small change in input signal voltage causes a noticeable change in emitter current. This causes the *same change in collector current (IE=IB+IC). And the collector current IC flowing through a load resistance produces a large voltage across it (Ohm’s Law). Thus, a low signal applied in the input B-E circuit appears in the amplified form in the output collector circuit. grade 9 electricity Hence in this way, a BJT transistor acts as an amplifier. power outage houston today Practical Application of BJT Transistor as an Amplifier:

The action of a BJT (Bipolar Junction Transistor) as an amplifier can be made simpler. if we consider typical circuit values. Suppose collector load resistance RC = 5 kΩ. Let us further assume that a change of 0.1V in signal voltage produces a change of 2 mA in emitter current. electricity png Obviously, the change in collector current would also be approximately 2 mA. This collector current flowing through collector load RC would produce a voltage = 5 kΩ × 2 mA = 10 V. m gastrocnemius Thus, a change of 0.1 V in the signal has caused a change of 10 V in the output circuit. electricity origin In other words, the transistor has been able to raise the voltage level of the signal from 0.1 V to 10 V i.e. voltage amplification factor (output/input)V is 100.

It is the region in which BJT (Bipolar Junction Transistor) act as an ON switch, in this region both Base-Emitter and Base-Collector junctions of the BJT transistor are forward biased. In this region, very high currents flow through the output of transistor, as both input and output junctions of the BJT are forward biased and bulk resistance offered is very much less. Hence BJT Transistor in the saturation region is considered as ON switch. Cutoff

When both junctions of BJT (Bipolar Junction Transistor) are made reverse bias then the transistor will act is an open switch, which means input base voltage will be zero IB=0, the transistor is in the cutoff region of its operation. When both junctions are reverse bias there will be no base current. gas 87 Under this condition, there is a very small amount of collector current that is known as collector leakage current, ICEO, and this is due to thermally produced carriers. And it is extremely small and hence it is usually neglected in circuit analysis so that VCE= VCC.

A Bipolar Junction Transistor has two main applications, one is Amplification and other is switching. They are mostly used as amplifiers in electronic circuits like Audio amplification, Voltage or current amplification. They are the heart of every electronic circuit because every electronic circuit requires audio, video, current or voltage amplification at some stage of their working so they are used there.