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Saturday, 31 October

JEE Main 2022 · PhysicsMultiple choiceDiagram basedMediumData or graph

JEE Main 28 June 2022, Shift 1, Physics Q40

Question 40 of 90 in this shift, Physics question 10 of 30, Section A.

An infinitely long hollow conducting cylinder with radius R carries a uniform current along its surface. Choose the correct representation of magnetic field (B) as a function of radial distance (r) from the axis of cylinder.

The figure, in words

Four graphs of B (vertical axis) against r (horizontal axis), with R marked on the r axis; described in the options.
  1. (1)[figure: graph of B vs r; B rises as a straight line from the origin O up to r = R (dashed vertical line at R), then stays constant (horizontal line) for r > R]
  2. (2)[figure: graph of B vs r; B rises as a straight line from the origin O up to r = R (dashed vertical line at R), then falls as a decaying curve for r > R]
  3. (3)[figure: graph of B vs r; B is a constant horizontal line from r = 0 up to r = R (dashed vertical line at R), then falls as a decaying curve for r > R]
  4. (4)[figure: graph of B vs r; B is zero from the origin O to r = R, then at r = R (dashed vertical line) it starts at a high value and falls as a decaying curve for r > R]Official answer

Official answer

Option 4

NTA final key.

Same topic in other shifts

All Ampere's Circuital Law questions
  1. 4 Apr 2026, Shift 2 · Q39A solenoid has a core made of material with relative permeability 400. The magnetic field produced in the interior of solenoid is 1.0 T.…EasySingle correct
  2. 5 Apr 2024, Shift 1 · Q43In a co-axial straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic…EasySingle correct
  3. 5 Apr 2024, Shift 2 · Q57A solenoid of length 0.5 m has a radius of 1 cm and is made up of 'm' number of turns. It carries a current of 5 A. If the magnitude of…EasyNumerical value
  4. 8 Apr 2024, Shift 2 · Q42A long straight wire of radius a carries a steady current I. The current is uniformly distributed across its cross section. The ratio of…MediumSingle correct
  5. 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
  6. 8 Apr 2023, Shift 1 · Q58The magnetic intensity at the center of a long current carrying solenoid is found to be 1.6×103 Am−11.6\times10^3\ \mathrm{Am^{-1}}. If the number…EasyNumerical value

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.