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Saturday, 31 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 12× 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. 4 Apr 2024, Shift 1 · Q48The value of net resistance of the network as shown in the given figure is :MediumDiagram basedHas a figure
  3. 15 Apr 2023, Shift 1 · Q43In the given circuit, the current (I) through the battery will beMediumDiagram basedHas a figure
  4. 25 Jul 2022, Shift 2 · Q56Two ideal diodes are connected in the network as shown is figure. The equivalent resistance between A and B is _______ Ω\Omega .MediumNumerical valueHas a figure
  5. 27 Jun 2022, Shift 2 · Q60The cut-off voltage of the diodes (shown in figure) in forward bias is 0.6 V. The current through the resister of 40 Ω\Omega is ________…MediumNumerical valueHas a figure
  6. 27 Aug 2021, Shift 1 · Q21A circuit is arranged as shown in figure. The output voltage Vo\mathrm{V_o} is equal to __________ V.MediumNumerical valueHas a figure
  7. 25 Feb 2021, Shift 1 · Q7A 5 V battery is connected across the points X and Y. Assume D1D_1 and D2D_2 to be normal silicon diodes. Find the current supplied by the…MediumDiagram basedHas a figure
  8. 26 Feb 2021, Shift 1 · Q28The circuit contains two diodes each with a forward resistance of 50 Ω\Omega and with infinite reverse resistance. If the battery voltage…MediumNumerical valueHas 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 108 of the 174 JEE Main shifts held from 2017 to 2026.