When a transistor operates as an amplifier, what happens to collector current with increased base current?

When a transistor operates as an amplifier, it exhibits a relationship between the base current and the collector current. In a bipolar junction transistor (BJT), the collector current is directly related to the base current through the transistor's current gain, often denoted as beta (β).

As the base current increases, it effectively increases the number of charge carriers (either holes or electrons, depending on whether it's a PNP or NPN transistor) flowing into the base region. This increase allows more carriers to flow from the collector to the emitter, thus increasing the collector current significantly. The collector current is usually a multiple of the base current, demonstrating the amplification capability of the transistor.

While the emitter current does also rise with an increase in base current (since it is the sum of the collector and base currents), the question specifically focuses on how the collector current responds to changes in base current. Therefore, the primary effect highlighted here is the increase in collector current due to the boost in base current.

In this scenario, the other options do not accurately capture the relationship between base and collector currents; they either misstate which current increases or do not address the amplifying nature of the transistor correctly.