An npn bipolar junction transistor (BJT) is operating in the active region. If the reverse bias across the base-collector junction is increased, thenThe effective base-width increases and common-emitter current gain decreasesThe effective base-width increases and common-emitter current gain increases The effective base-width decreases and common-emitter current gain decreasesThe effective base-width decreases and common-emitter current gain increases
Question
An npn bipolar junction transistor (BJT) is operating in the active region. If the reverse bias across the base-collector junction is increased, thenThe effective base-width increases and common-emitter current gain decreasesThe effective base-width increases and common-emitter current gain increases The effective base-width decreases and common-emitter current gain decreasesThe effective base-width decreases and common-emitter current gain increases
Solution
The correct answer is: The effective base-width increases and common-emitter current gain decreases.
Here's why:
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In an NPN transistor operating in the active region, the base-emitter junction is forward biased and the base-collector junction is reverse biased.
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When the reverse bias across the base-collector junction is increased, the depletion region at this junction widens. This effectively increases the width of the base region.
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The base width is inversely proportional to the common-emitter current gain (β). This is because as the base width increases, recombination of charge carriers within the base region also increases. This reduces the number of charge carriers available for conduction, thereby reducing the current gain.
So, when the reverse bias is increased, the effective base-width increases and the common-emitter current gain decreases.
Similar Questions
A BJT is said to be operating in the saturation region ifBase-emitter junction is reverse biased and base-collector junction is forward biasedBoth the junctions are reverse biasedBoth the junctions are forward biasedBase-emitter junction is forward biased and base-collector junction is reverse biased
If the base width in a bipolar junction transistor is doubled, which one of the following statements will be TRUE?Current gain will increaseEarly voltage will increaseEmitter base junction capacitance will increaseUnity gain frequency will increase
For a common base configuration of npn transistor, collector current is greater than base current. Why?
A- The emitter injects holes into the base region Which of the following is VALID for both P-N-P as well as N-P-N transistor LO: PH.2.16 B- The electrons are the minority carriers in the base region C. The emitter base junction is forward biased for active operation - When a biased in the active region, current flows into their emitter terminal
What happens to the collector current (Ic) when the base current (Ib) increases in a BJT operating in the active region?
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