Q.5
For the picture shown above, which one of the following is the correct picture
representing reflection with respect to the mirror shown as the dotted line?
Mastering Mirror Reflection of Octagon Shapes: CSIR NET Practice Question Solved
Mirror reflection problems test symmetry and visualization skills, crucial for CSIR NET Life Sciences spatial reasoning sections. This question involves identifying the correct reflection of a partially shaded octagon across a dotted mirror line.
Question Analysis
The original figure shows an irregular octagon with specific shaded segments positioned relative to a vertical dashed mirror line. Reflection requires flipping shaded parts across this line while preserving distances perpendicular to it. Each option presents a complete figure; the correct one matches the original’s reflection exactly.
Option Breakdown
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Option A: Features two adjacent shaded octagons without proper mirroring. Shaded areas do not symmetrically oppose the original across the dotted line, creating asymmetry in segment placement.
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Option B: Displays a large P-shaped overlay on shaded regions. This ignores pure reflection rules, adding extraneous elements instead of mirroring existing shades accurately.
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Option C: Shows two separate octagons with partial shading. While closer, the relative positions and shade orientations fail to replicate perpendicular distances from the mirror line.
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Option D: Correctly reflects the original shaded segments across the dotted line. Left-right reversal maintains top-bottom orientation, producing identical symmetry to the expected image.
Correct Answer: D – Matches mirror image principles where parts swap sides across the line.
Reflection Rules Explained
To solve, draw perpendiculars from each shaded point to the mirror line, then plot equidistant points on the opposite side. Vertical mirrors reverse left-right but not up-down. Practice with grids ensures accuracy for exams.
