GATE 2025 MT – Question 62
A cylindrical specimen is plastically deformed in tension to a uniform elongation of 10%. The final gage cross-sectional area is 20 mm$^2$. Its initial gage cross-sectional area is ______ mm$^2$ (rounded to an integer).
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Correct answer: 22 to 22
Explanation
Plastic deformation conserves volume: $A_iL_i=A_fL_f$. A 10% engineering elongation means $L_f=1.10L_i$.
Therefore $A_i=A_f(L_f/L_i)=20\times1.10=\boxed{22\ \mathrm{mm^2}}$.