GATE 2015 EE (EE2) – Question 22

Analog and Digital Electronics · Amplifiers: biasing, equivalent circuit and frequency response · 1 mark · Numerical answer

The transistor is active and initially VC=2 V. To obtain VC=4 V, RC is replaced by RC′. Find RC′/RC.

Diagram for GATE 2015 EE (EE2) question 22

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 0.74 to 0.76

Explanation

The base bias is supplied through RB from the fixed 10 V rail. Under the constant-β active-region model, replacing the collector resistor does not change base or collector current.

Initially the collector resistor drops 10−2=8 V. Finally it must drop 10−4=6 V at the same current. Therefore RC′/RC=6/8=**0.75**, within 0.74–0.76.

More Amplifiers: biasing, equivalent circuit and frequency response questions

GATE 2015 EE (EE2) Q25 – For a BJT operating in saturation, which statement about collector–base and base–emitter…
GATE 2025 EE Q16 – Which one of the following statements is true about the small signal voltage gain of a…
GATE 2025 EE Q38 – In the circuit, I DC is an ideal current source. The transistors M 1 and M 2 are assumed…
GATE 2024 EE Q42 – A BJT biasing circuit is shown in the figure, where V BE=0.7 V and =100. The Quiescent…
GATE 2023 EE Q59 – The Zener diode in circuit has a breakdown voltage of 5 V. The current gain of the…
GATE 2022 EE Q12 – For an ideal MOSFET biased in saturation, the magnitude of the small signal current gain…

All Amplifiers: biasing, equivalent circuit and frequency response questions →