GATE 2023 BM – Question 44
In the shown circuit the sinusoidal input is 2.5 V peak to peak. Both capacitors are 20 μF, diode knee voltage is zero, and Rₗ is almost infinite. After many cycles, which option is closest to the voltage across Rₗ? The original source asks for “peak to peak voltage.”
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Correct answer: (C) 5.00 V
Explanation
The circuit is a voltage doubler: D₁ clamps the intermediate negative excursion, C₁ charges to the input peak, and D₂ charges C₂ to twice that peak. There is a source/key inconsistency: a literal 2.5 V peak-to-peak input has peak 1.25 V and gives approximately 2.5 V DC with negligible ripple. The official C=5 V instead treats 2.5 V as the input peak; it also calls the DC output “peak to peak.” The official grading C is preserved, with this wording issue explicit rather than silently changing the supplied values.