GATE 2021 ME (ME2) – Question 51
The thickness, width and length of a metal slab are 50 mm, 250 mm and 3600 mm, respectively. A rolling operation on this slab reduces the thickness by 10% and increases the width by 3%. The length of the rolled slab is _____ mm (round off to one decimal place).
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Correct answer: 3864.08 to 3902.92
Explanation
Plastic forming conserves volume. New thickness is 0.9 t and width 1.03 b, so $L_f=L_0/(0.9\times1.03)$.
Thus $L_f=3600/0.927=3883.49515$ mm, rounded to **3883.5 mm**. Both transverse changes affect length.