Question

The Early Effect is also called as

(a) Base-width modulation effect

(b) Base-width amplification effect

(c) Both of the mentioned

(d) None of the mentioned

The question was posed to me during an interview for a job.

This intriguing question originated from BJTs Current-Voltage Characteristics in division Bipolar Junction Triodes (BJTs) of Electronic Devices & Circuits

Answer 1

The correct option is (a) Base-width modulation effect

Easiest explanation: At a given value of vBE, increasing vCE increases the reverse-bias voltage on the collector–base junction, and thus increases the width of the depletion region of this junction. This in turn results in a decrease in the effective base width W. Also the saturation current is inversely proportional to the width, the saturation current will increase and also makes collector current increases proportionally. This is the Early Effect. For the reasons mentioned above, it is also known as the base-width modulation effect.