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Friday, 9 October

JEE Main 2025 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 4 April 2025, Shift 2, Physics Q31

Question 31 of 75 in this shift, Physics question 6 of 25, Section A.

Consider a rectangular sheet of solid material of length l=9l=9 cm and width d=4d=4 cm. The coefficient of linear expansion is α=3.1×10−5 K−1\alpha=3.1\times10^{-5}\,\mathrm{K^{-1}} at room temperature and one atmospheric pressure. The mass of sheet m=0.1m=0.1 kg and the specific heat capacity Cv=900 J kg−1K−1C_v=900\ \mathrm{J\,kg^{-1}K^{-1}}. If the amount of heat supplied to the material is 8.1×1028.1\times10^{2} J then change in area of the rectangular sheet is :
  1. (1)2.0×10−6 m22.0\times10^{-6}\ \mathrm{m^2}Official answer
  2. (2)4.0×10−7 m24.0\times10^{-7}\ \mathrm{m^2}
  3. (3)6.0×10−7 m26.0\times10^{-7}\ \mathrm{m^2}
  4. (4)3.0×10−7 m23.0\times10^{-7}\ \mathrm{m^2}

Official answer

Option 1

NTA final key.

Chapter
Thermal Properties of Matter
Topic
Thermal Expansion
Idea tested
Superficial Expansion

Same topic in other shifts

All Thermal Expansion questions
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  6. 2 Apr 2017 (offline) · Q9An external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides. K is the bulk modulus of the material…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. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.