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Friday, 9 October

JEE Main 2026 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 4 April 2026, Shift 1, Physics Q42

Question 42 of 75 in this shift, Physics question 17 of 25, Section A.

Consider a circuit consisting of a capacitor (20 μ20\ \muF), resistor (100 Ω100\ \Omega) and two identical diodes as shown in figure. The resistance of diode under forward biasing condition is 10 Ω10\ \Omega. The time constant of the circuit is α×10−3\alpha\times10^{-3} s. The value of α\alpha is ______.

The figure, in words

Series loop: battery VV, capacitor C=20 μC=20\ \muF, resistor R=100 ΩR=100\ \Omega, then two identical diodes connected in parallel with opposite orientations (anti-parallel), back to the battery.
  1. (1)2.22.2Official answer
  2. (2)2.02.0
  3. (3)2.12.1
  4. (4)2.42.4

Official answer

Option 1

NTA final key.

Chapter
Alternating Current
Topic
Semiconductor Diodes
Idea tested
Ideal vs. Practical Diode Circuit Analysis

Same idea in other shifts

Asked 3× in all
  1. 8 Apr 2025, Shift 2 · Q45The output voltage in the following circuit is (Consider ideal diode case)MediumDiagram basedHas a figure
  2. 9 Jan 2020, Shift 2 · Q20The current ii in the network is :MediumSingle correctHas a figure

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.