Hi, can anyone please look at the attached file and try to ans. the 4th question. there i can't figure out the "role" of two resistors Rb1 and Rb2 and the capacitor C2. Here's what I figured: The ground point with the Capacitor C2 makes the resistors R1 and R2 in parallel. And the current Ic is divided into two - Ic = which flows through the transistor and the current Ic' = which flows through the resistor&capacitor configuration. This Ic' is further divided into Ic1' and Ic2' . Ic1' = going to ground through capacitor Ic2' = going towards the base through Resistor Rb1. Please ans. if this is correct and please try to provide some explanation as to what happens. Thanks a lot for you generous help!!! Waiting for you reply! (eagerly).