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Physics · PYQ NEET UG 2024
हिन्दीA metallic bar of Young's modulus, \( 0.5 \times 10^{11}\text{ N m}^{-2} \) and coefficient of linear thermal expansion \( 10^{-5}\text{ }^\circ\text{C}^{-1} \), length \( 1\text{ m} \) and area of cross-section \( 10^{-3}\text{ m}^2 \) is heated from \( 0^\circ\text{C} \) to \( 100^\circ\text{C} \) without expansion or bending. The compressive force developed in it is:
Correct answer · Option 4
\( 50 \times 10^3\text{ N} \)
Explanation
Thermal stress developed when expansion is prevented is given by \( F/A = Y \alpha \Delta T \). Thus, thermal force \( F = Y A \alpha \Delta T = (0.5 \times 10^{11}) \times (10^{-3}) \times (10^{-5}) \times (100) = 50 \times 10^3\text{ N} \).
