JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 4 August 2021, Shift 2, Physics Q14

Question 14 of 90 in this shift, Physics question 14 of 30, Section A.

A copper rod of length 1m is stretched by 30 mm within elastic limit. The energy stored in the stretched rod is converted into heat, then the rise in temperature of the rod is __________. [Given Young’s Modulus

\gamma=1.05\times10^{11}\,\mathrm{N/m^2}

Specific gravity of copper = 9 specific heat capacity S = 100 Cal/kg/°C]

(1)1.25°C
(2)12.5°COfficial answer
(3)15.0°C
(4)15.5°C

Official answer

Option 2

NTA final key.

Chapter: Mechanical Properties of Solids
Topic: Elasticity
Idea tested: Elastic Potential Energy

Same idea in other shifts

Asked 4× in all

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22 Jul 2021, Shift 2 · Q25The area of cross-section of a railway track is $0.01\ \mathrm{m^2}$ . The temperature variation is $10^\circ$ C. Coefficient of linear…MediumNumerical 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.