GATE 2022 PI – Question 31

Quality and Reliability · Metrology and Inspection · 1 mark · Numerical answer

Absolute surface deviations from a datum line are 10,15,12,10,13,12,20,25 µm. Find RMS roughness in µm to one decimal.

Show answer and explanation

Correct answer: 15.0 to 16.0

Explanation

$R_q=\sqrt{\sum y_i^2/8}$. Sum of squares is 100+225+144+100+169+144+400+625 = 1907. Thus $R_q=\sqrt{1907/8}=15.439$ µm, or **15.4 µm**.

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