Which of the following is true for a typical active region of an npn t...
Most commonly used transistors have Vce less than 0.4 V for the active region.
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Which of the following is true for a typical active region of an npn t...
Ans.
Option (c)
Most commonly used transistors have Vce less than 0.4 V for the active region.
Which of the following is true for a typical active region of an npn t...
Active Region of an NPN Transistor
In a typical active region of an npn transistor, the potential difference between the emitter and the collector is less than 0.3 V. This means that the collector voltage is higher than the emitter voltage by less than 0.3 V.
Explanation:
To understand why this is true, let's first review the basic operation of an npn transistor. An npn transistor consists of three layers of semiconductor material: the emitter, base, and collector. The base region is very thin compared to the emitter and collector regions.
The npn transistor operates as an amplifier, allowing a small current to control a larger current. In the active region, the npn transistor is biased such that the emitter-base junction is forward-biased and the base-collector junction is reverse-biased.
When a positive voltage is applied to the base-emitter junction, it forward-biases the junction and allows a current to flow from the emitter to the base. This current is amplified by the transistor and results in a larger current flowing from the collector to the emitter.
In the active region, the npn transistor operates as an amplifier, and the collector current is directly proportional to the base current. The collector current is given by the equation:
Ic = β * Ib
Where Ic is the collector current, Ib is the base current, and β is the current gain of the transistor.
Importance of Potential Difference:
The potential difference between the emitter and the collector is an important parameter in the operation of the npn transistor. It determines the amount of current that can flow through the transistor.
If the potential difference between the emitter and the collector is too high, it can lead to a breakdown of the base-collector junction, causing excessive current to flow and potentially damaging the transistor. Therefore, it is important to keep the potential difference within a safe operating range.
Answer Choice:
Among the given answer choices, option 'C' states that the potential difference between the emitter and the collector is less than 0.3 V, which is a typical value for the active region of an npn transistor. This answer choice correctly identifies the operating condition of the transistor in the active region.
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