GATE EC 2026 Set 1 Q40 — Electronic Devices

A small signal source, $V_{i}(t)=A \cos \left(10^{5} t\right)+B \sin \left(10^{7} t\right)$ is applied to a BJT circuit as shown in the Figure.

Assume zero source resistance, $V_{B E}=0.7 \mathrm{~V}, \beta_{d c}=99$, Early voltage $=100 \mathrm{~V}$ and 

Thermal voltage $=25 \mathrm{mV}$. Effect of internal parasitic capacitances of the BJT may be neglected.

Which expression is the best approximation of the output voltage $V_{o}(t)$?