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Friday, 9 October

JEE Main 2022 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 25 July 2022, Shift 1, Physics Q54

Question 54 of 90 in this shift, Physics question 24 of 30, Section B.

A unit scale is to be prepared whose length does not change with temperature and remains 2020 cm, using a bimetallic strip made of brass and iron each of different length. The length of both components would change in such a way that difference between their lengths remains constant. If length of brass is 4040 cm and length of iron will be ______ cm. (αiron=1.2×10−5 K−1\alpha_{\mathrm{iron}}=1.2\times10^{-5}\ \mathrm{K^{-1}} and αbrass=1.8×10−5 K−1\alpha_{\mathrm{brass}}=1.8\times10^{-5}\ \mathrm{K^{-1}}).

Official answer

60

NTA final key (2022 Session 2).

Chapter
Thermal Properties of Matter
Topic
Thermal Expansion
Idea tested
Constant Length Difference

Same topic in other shifts

All Thermal Expansion questions
  1. 4 Apr 2026, Shift 2 · Q34The temperature of a metal strip having coefficient of linear expansion α\alpha is increased from T1T_1 to T2T_2 resulting in increase of…MediumSingle correct
  2. 5 Apr 2026, Shift 2 · Q34An ideal gas at pressure PP and temperature TT is expanding such that PT3PT^3 = constant. The coefficient of volume expansion of the gas…MediumSingle correct
  3. 4 Apr 2025, Shift 2 · Q31Consider a rectangular sheet of solid material of length l=9l=9 cm and width d=4d=4 cm. The coefficient of linear expansion is…MediumSingle correct
  4. 8 Apr 2023, Shift 2 · Q52A steel rod of length 1 m and cross sectional area 10−410^{-4} m2^2 is heated from 0∘0^\circC to 200∘200^\circC without being allowed to…EasyNumerical value
  5. 16 Mar 2021, Shift 2 · Q13A bimetallic strip consists of metals A and B. It is mounted rigidly as shown. The metal A has higher coefficient of expansion compared to…EasyDiagram basedHas a figure
  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.