Learn

Saturday, 31 October

JEE Main 2021 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 22 July 2021, Shift 2, Physics Q28

Question 28 of 90 in this shift, Physics question 28 of 30, Section B.

In a given circuit diagram, a 5 V zener diode along with a series resistance is connected across a 50 V power supply. The minimum value of the resistance required, if the maximum zener current is 90 mA will be ________ Ω\Omega.

The figure, in words

Circuit: input V_i = 50 V on the left; current I flows through a series resistor R (zigzag) along the top wire; at a junction the current I_1 flows down through a zener diode labelled Z, and I_2 continues right to a load resistor labelled R_L in a parallel branch; output terminals on the right labelled V_Z; bottom wire joins all branches.

Official answer

500

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. 2 Apr 2025, Shift 1 · Q45A 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…MediumSingle correct
  2. 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
  3. 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
  4. 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
  5. 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
  6. 26 Jul 2022, Shift 1 · Q60In the circuit shown below, maximum zener diode current will be __________ mA.MediumNumerical valueHas a figure
  7. 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
  8. 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

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.