List of top Networks, Signals and Systems Questions on Transistors

In the circuit shown, the identical transistors Q1 and Q2 are biased in the active region with $ \beta = 120 $. The Zener diode is in the breakdown region with $ V_Z = 5 \, V $ and $ I_Z = 25 \, mA $. If $ I_L = 12 \, mA $ and $ V_{EB1} = V_{EB2} = 0.7 \, V $, then the values of $ R_1 $ and $ R_2 $ (in $ k\Omega $, rounded off to one decimal place) are _________, respectively.

GATE EC - 2025
GATE EC
Networks, Signals and Systems
Transistors

The electron mobility $ \mu_n $ in a non-degenerate germanium semiconductor at 300 K is 0.38 m$^2$/Vs. The electron diffusivity $ D_n $ at 300 K (in cm$^2$/s, rounded off to the nearest integer) is _________.

GATE EC - 2025
GATE EC
Networks, Signals and Systems
Transistors

A square metal sheet of 4 m $ \times $ 4 m is placed on the x-y plane as shown in the figure below. If the surface charge density (in $ \mu $C/m$^2$) on the sheet is $ \rho_s(x, y) = 4|y| $, then the total charge (in $ \mu $C, rounded off to the nearest integer) on the sheet is _________.

GATE EC - 2025
GATE EC
Networks, Signals and Systems
Transistors