GATE 2024 PH – Question 58

Electronics · p-n diodes, bipolar junction transistors, field effect transistors · 2 marks · Numerical answer

A typical biasing of a silicon transistor is shown in figure. The value of common-emitter current gain β for the transistor is 100. Ignore reverse saturation current. The output voltage V0 (in V) is ____ (in integer).

NPN transistor biased by 1 V through 15 kΩ and −12 V through 100 kΩ, with 12 V collector supply and 2.2 kΩ load.

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Correct answer: 12

Explanation

Without base current the divider gives $V_B=(1/15000-12/100000)/(1/15000+1/100000)=-0.696$ V. The grounded-emitter NPN is cut off. No collector current means no load drop, so $V_0=12$ V.