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What is active region in NPN transistor?
Active region is that region in which emitter base junction is forward bias while collector base junction is also forward bias. B. Active region is that region in which emitter base junction is forward bias while collector base junction is reverse bias.
Is there depletion region in NPN transistor?
During this process, the free electrons meet the holes in the p-region (base) near the junction and fill them. As a result, depletion region (positive and negative ions) is formed at the emitter to base junction and base to collector junction.
What is the function of transistor in active region?
Active region lies between saturation and cutoff. The transistor in this operates in an active region, when the collector junction is reverse biased and emitter junction is forward biased. The transistor will function normally. Cut-Off: In the cut-off region, the emitter diode and collector diode are off.
What happens active region?
The region between cut off and saturation is known as active region. In the active region, collector-base junction remains reverse biased while base-emitter junction remains forward biased. Consequently, the transistor will function normally in this region.
In a common emitter NPN transistor the relation between collector current and emitter current is given as. I C = β I B. In active region the NPN transistor acts as a good amplifier. In common emitter NPN transistor total current flow through the transistor is defined as the ratio of collector current to the base current IC/IB.
What makes a bipolar NPN transistor a good amplifying device?
The value of β can be large up to 200 for standard transistors, and it is this large ratio between Ic and Ib that makes the bipolar NPN transistor a useful amplifying device when used in its active region as Ib provides the input and Ic provides the output. Note that Beta has no units as it is a ratio.
How does the NPN transistor work in dcaclab?
1 In NPN, we supply a positive current to the base, the current flows through the collector to the emitter. 2 The current direction in NPN is from collector to emitter and in PNP from emitter to collector. 3 Switching time is faster in NPN & slower in PNP. 4 NPN turns ON when the electron enters the base region.
How are NPN transistors used in Darlington circuit?
Used in the Darlington pair circuits to amplify weak signals. NPN transistors are used in the applications where there is a need to sink a current. Used in some classic amplifier circuits, such as ‘push-pull’ amplifier circuits.