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Friday, 9 October

JEE Main 2026 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 4 April 2026, Shift 2, Physics Q39

Question 39 of 75 in this shift, Physics question 14 of 25, Section A.

A solenoid has a core made of material with relative permeability 400. The magnetic field produced in the interior of solenoid is 1.0 T. The magnetic intensity in SI units is α×105\alpha\times10^5. The value of α\alpha is ________. (Free space permeability μ0=4π×10−7\mu_0=4\pi\times10^{-7} SI units.)
  1. (1)25π\frac{25}{\pi}
  2. (2)116π\frac{1}{16\pi}Official answer
  3. (3)1π\frac1\pi
  4. (4)14π\frac{1}{4\pi}

Official answer

Option 2

NTA final key.

Chapter
Magnetism and Matter
Topic
Ampere's Circuital Law
Idea tested
Ampere's Law for Magnetic Intensity (H)

Same topic in other shifts

All Ampere's Circuital Law questions
  1. 6 Apr 2023, Shift 1 · Q40A long straight wire of circular cross-section (radius a) is carrying steady current I. The current I is uniformly distributed across this…EasySingle correct
  2. 18 Mar 2021, Shift 1 · Q3Four identical long solenoids A, B, C and D are connected to each other as shown in the figure. If the magnetic field at the center of A…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. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.