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Saturday, 31 October

JEE Main 2025 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 2 April 2025, Shift 1, Physics Q45

Question 45 of 75 in this shift, Physics question 20 of 25, Section A.

A zener diode with 5 V zener voltage is used to regulate an unregulated dc voltage input of 25 V. For a 400 Ω400\ \Omega resistor connected in series, the zener current is found to be 4 times load current. The load current (ILI_L) and load resistance (RLR_L) are :
  1. (1)IL=0.02I_L=0.02 mA; RL=250 ΩR_L=250\ \Omega
  2. (2)IL=20I_L=20 mA; RL=250 ΩR_L=250\ \Omega
  3. (3)IL=10I_L=10 mA; RL=500 ΩR_L=500\ \OmegaOfficial answer
  4. (4)IL=10I_L=10 A; RL=0.5 ΩR_L=0.5\ \Omega

Official answer

Option 3

NTA final key.

Chapter
Semiconductor Electronics: Materials, Devices and Simple Circuits
Topic
Semiconductor Diodes
Idea tested
Zener Diode Regulation

Same idea in other shifts

Asked 15× in all
  1. 7 Apr 2025, Shift 1 · Q45In the following circuit, the reading of the ammeter will be (Take Zener breakdown voltage = 4 V)MediumDiagram basedHas a figure
  2. 8 Apr 2024, Shift 2 · Q60A potential divider circuit is connected with a dc source of 20 V, a light emitting diode of glow in voltage 1.8 V and a zener diode of…MediumNumerical valueHas a figure
  3. 29 Jan 2024, Shift 1 · Q48In the given circuit, the breakdown voltage of the Zener diode is 3.0 V. What is the value of IzI_z?MediumDiagram basedHas a figure
  4. 30 Jan 2024, Shift 1 · Q48A Zener diode of breakdown voltage 10 V is used as a voltage regulator as shown in the figure. The current through the Zener diode is :MediumDiagram basedHas a figure
  5. 26 Jul 2022, Shift 1 · Q60In the circuit shown below, maximum zener diode current will be __________ mA.MediumNumerical valueHas a figure
  6. 29 Jul 2022, Shift 2 · Q58A 8 V Zener diode along with a series resistance R is connected across a 20 V supply (as shown in the figure). If the maximum Zener…MediumNumerical valueHas a figure
  7. 24 Jun 2022, Shift 2 · Q55In the given circuit, the value of current ILI_L will be ________ mA. (When RLR_L = 1kΩ\Omega)MediumNumerical valueHas a figure
  8. 28 Jun 2022, Shift 2 · Q52A zener of breakdown voltage VZ_Z=8 V and maximum zener current, IZM_{ZM}=10 mA is subjected to an input voltage Vi_i=10 V with series…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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.