GATE CS 2021 Set 2 Q.2 (GA Q.2): Spatial Aptitude

Transparent square sheet with a vertical dashed fold line through the middle. A curve rises from the lower left to a peak on the fold line and falls to the lower right. Two short vertical ticks stand on the curve left of the fold; two short horizontal dashes hang beside the curve right of the fold. — Transparent square sheet before folding

A transparent square sheet shown above is folded along the dotted line. The folded sheet will look like ________.

Option A: folded sheet (the left half shown dashed, folded onto the right half). Two curves start at the left edge and spread apart, one rising to the upper right with two short vertical ticks, the other falling to the lower right with two short horizontal dashes.

Option B: folded sheet (left half dashed). Two curves meet at the left edge and at the lower right corner forming a lens shape; inside the lens are two short marks drawn as steps.

Option C: folded sheet (left half dashed). Two curves form a lens shape from the left edge to the lower right; inside the lens are two short horizontal dashes.

Option D: folded sheet (left half dashed). Two curves form a lens shape from the left edge to the lower right; inside the lens are two short marks drawn as steps along the curve.

Official answer and solution

Official answer: B
From: Official GATE 2021 answer key

Solution

Apply mirror reflection across the vertical dashed centerline to trace overlapping features.

The square sheet has a vertical dashed fold line along its middle. When folded from left to right along this line, the left half reflects across the vertical centerline and overlays onto the right half.

The diagonal on the left rises from the bottom-left corner to the center of the fold line. Upon reflection, it coincides with the diagonal line already present on the right half.

The left half contains two vertical segments, which reflect across the centerline to corresponding vertical lines on the right half. The right half contains two horizontal segments. The combination forms a grid/cross pattern where the reflected vertical segments intersect the horizontal segments, matching Option B.

Final answer

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper: GATE 2021 Computer Science and Information Technology - Session 2 (CS2)
Question: 2 of 65, printed as GA Q.2
Section: General Aptitude

Report an error in this question

GATE questions are the work of the organising institutes. This site is independent and is not affiliated with them.

Question

Solution

Source