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Saturday, 31 October

JEE Main 2024 · PhysicsNumerical answerNumerical valueHardMulti-step

JEE Main 6 April 2024, Shift 2, Physics Q60

Question 60 of 90 in this shift, Physics question 30 of 30, Section B.

A wire of cross sectional area AA, modulus of elasticity 2×1011 Nm−22\times10^{11}\ \mathrm{Nm^{-2}} and length 2 m is stretched between two vertical rigid supports. When a mass of 2 kg is suspended at the middle it sags lower from its original position making angle θ=1100\theta=\frac{1}{100} radian on the points of support. The value of AA is ________ ×10−4 m2\times10^{-4}\ \mathrm{m^2} (consider x≪Lx\ll L). (given : g=10 m/s2g=10\ \mathrm{m/s^2})

The figure, in words

Wire of total span 2L between two rigid vertical supports at the same level; a 2 kg mass hangs from the midpoint, which sags down by x; the wire makes angle theta with the horizontal at each support.

Official answer

1

NTA final key.

Chapter
Mechanical Properties of Solids
Topic
Elasticity
Idea tested
Hooke's Law

Same idea in other shifts

Asked 5× in all
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  4. 31 Aug 2021, Shift 2 · Q11Four identical hollow cylindrical columns of mild steel support a big structure of mass 50×10350\times10^3 kg. The inner and outer radii of…MediumSingle correct

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.