For a transistor to act as current amplifier.a)Both its emitter base j...
For any amplification, (voltage or current), the transistor should be operated in active region ie. emitter base junction is forward biased and collector base junction is reverse biased
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For a transistor to act as current amplifier.a)Both its emitter base j...
To understand why option 'C' is the correct answer, let's first discuss the basic functioning of a transistor.
A transistor is a three-layer semiconductor device that consists of two pn-junctions. These pn-junctions are formed by bringing together two different types of semiconductor materials, namely P-type and N-type.
The three layers in a transistor are named as emitter, base, and collector. The emitter-base junction and the collector-base junction are the two pn-junctions in a transistor.
Now, let's analyze each option to determine the correct answer:
a) Both its emitter-base junction and collector-base junction are forward biased:
If both junctions are forward biased, it means that the P-side of the junction is connected to the positive terminal of the power supply and the N-side is connected to the negative terminal. In this biasing condition, the transistor will not act as a current amplifier. Instead, it will be in a saturation region, where the transistor operates as a switch.
b) Both its emitter-base junction and collector-base thin junction are reverse biased:
If both junctions are reverse biased, it means that the N-side of the junction is connected to the positive terminal of the power supply and the P-side is connected to the negative terminal. In this condition, no current flows through the transistor, and it does not act as a current amplifier.
d) Its emitter-base junction is reverse biased while the collector-base junction is forward biased:
If the emitter-base junction is reverse biased and the collector-base junction is forward biased, this biasing condition is known as the active region of operation. In this region, the transistor acts as a current amplifier. The reverse biased emitter-base junction allows the transistor to control the current flow from the emitter to the base. The forward biased collector-base junction allows the amplified current to flow from the collector to the emitter.
Therefore, option 'C' is the correct answer: Its emitter-base junction is forward biased while the collector-base junction is reverse biased.
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