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Saturday, 31 October

JEE Main 2020 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 3 September 2020, Shift 1, Physics Q20

Question 20 of 75 in this shift, Physics question 20 of 25.

When a diode is forward biased, it has a voltage drop of 0.5 V. The safe limit of current through the diode is 10 mA. If a battery of emf 1.5 V is used in the circuit, the value of minimum resistance to be connected in series with the diode so that the current does not exceed the safe limit is :
  1. (1)200 Ω\Omega
  2. (2)100 Ω\OmegaOfficial answer
  3. (3)50 Ω\Omega
  4. (4)300 Ω\Omega

Official answer

Option 2

NTA final key (Sep 2020).

Chapter
Semiconductor Electronics: Materials, Devices and Simple Circuits
Topic
Semiconductor Diodes
Idea tested
Ideal vs. Practical Diode Circuit Analysis

Same idea in other shifts

Asked 12× in all
  1. 4 Apr 2026, Shift 1 · Q42Consider a circuit consisting of a capacitor (20 μ20\ \muF), resistor (100 Ω100\ \Omega) and two identical diodes as shown in figure. The…MediumDiagram basedHas a figure
  2. 8 Apr 2025, Shift 2 · Q45The output voltage in the following circuit is (Consider ideal diode case)MediumDiagram basedHas a figure
  3. 4 Apr 2024, Shift 1 · Q48The value of net resistance of the network as shown in the given figure is :MediumDiagram basedHas a figure
  4. 15 Apr 2023, Shift 1 · Q43In the given circuit, the current (I) through the battery will beMediumDiagram basedHas a figure
  5. 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
  6. 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
  7. 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
  8. 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

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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.