GATE 2026 Electronics & Communication Q50

Question

A small signal source, Vi(t) = A cos(10^5t) + B sin(10^7t) is applied to a BJT circuit as shown in the Figure.
Assume zero source resistance, VBE = 0.7 V, βdc = 99, Early voltage = 100 V and
Thermal voltage = 25 mV. Effect of internal parasitic capacitances of the BJT may be neglected.
Which expression is the best approximation of the output voltage Vo(t)?

IIT Guwahati · Accepted Answer

-9.1[A cos(10^5t) + B sin(10^7t)]

IIT Guwahati · Answer

9.1[A cos(10^5t) – B sin(10^7t)]

IIT Guwahati · Answer

-190.4[A cos(10^5t) + B sin(10^7t)]

IIT Guwahati · Answer

190.4[A cos(10^5t) – B sin(10^7t)]