GATE 2018 ME (ME1) – Question 46
A continuous sheet-metal strip is blanked into circular pieces of diameter D as shown, with D/5 spacing between circles and D/5 margins on both edges. Scrap percentage, to two decimals, is ______%.
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Correct answer: 52.00 to 54.00
Explanation
Each repeat has pitch $1.2D$ and width $1.4D$, so strip area is $1.68D^2$. Circular blank area is $\pi D^2/4$. Scrap fraction is $1-\pi/(4\times1.68)$, or 53.25%. Ignore continuous-strip end effects.