0 votes 0 votes The current $i_b$ through the base of a silicon $npn$ transistor is $1+0.1\cos(10000\pi t)\:mA$. At $300\:K$, the $r_\pi$ in the small signal model of the transistor is $250\:\Omega$ $27.5\:\Omega$ $25\:\Omega$ $22.5\:\Omega$ Electronic Devices gate2012-ec electronic-devices intrinsic-and-extrinsic-silicon + – Milicevic3306 asked Mar 25, 2018 edited Nov 17, 2020 by soujanyareddy13 Milicevic3306 16.0k points 98 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.