The common base current gain a1 varies with the emitter current IA and a2 varies with IK (IA + IG). If the a gate current is applied, this would increase IA and directly lead to an increase in gain. Therefore a regenerative effect results. The removal of the gate current will not cause the device to turn off.
Active vs. passive voice. In a sentence written in the active voice, the subject of sentence performs the action. In a sentence written in the passive voice the subject receives the action. Active: The candidate believes that Congress must place a ceiling on the budget. Passive: It is believed by the candidate that a ceiling must be placed on the budget by Congress.
Active voice vs. passive voice. If the subject of a clause acts, the clause is in the active voice. If the subject is acted upon, the clause is in the passive voice. For example, I kissed Sheila is in the active voice because the subject (I) acts (kissed) upon the object of the verb (Sheila). I was kissed by Sheila is in the passive voice because the subject is being acted upon.