Question

In a BJT, what is the primary consequence of the Early effect on the effective base width?

• A. The base width increases
• B. The base width decreases
• C. The base width remains constant
• D. The base width becomes zero

Hint:

Early Effect → Base-width modulation → Effective base width decreases

Answer 1

The Correct Option is B

Concept:
The Early effect (also known as base-width modulation) occurs in a Bipolar Junction Transistor (BJT) when the collector-base junction voltage increases.
Step 1:Reverse bias of collector-base junction.
In normal transistor operation, the collector-base junction is reverse biased. Increasing this reverse bias causes the depletion region at the collector-base junction to widen.
Step 2:Effect on the base region.
As the depletion region expands into the base region, the effective width of the base decreases.
Step 3:Impact on transistor current.
A thinner base region allows more charge carriers to pass from emitter to collector, increasing the collector current slightly even if the base current remains constant. Conclusion:
Therefore, the primary consequence of the Early effect is that the effective base width decreases.