A hard rubber roller is cut with a V-shaped profile at three locations as shown in the Top View in the image on the left. The roller is then dipped in blue colour and rolled over a white plane. Which option shows the correct impression on the plane?
Show Hint
For rolling-impression problems:
\begin{itemize}
\item Raised surfaces print; grooves do not,
\item Track how a single cut repeats over one full rotation,
\item Symmetry of the roller dictates periodic patterns.
\end{itemize}
Step 1: From the top view of the roller, note that there are three identical V-shaped grooves cut around the circumference of the roller.
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Step 2: When the roller is dipped in colour and rolled on a flat surface:
\begin{itemize}
\item Raised portions of the roller leave coloured impressions,
\item The V-shaped cuts do \emph{not} leave colour and hence appear as white shapes,
\item Continuous rolling converts the V-shaped grooves into a repeated pattern.
\end{itemize}
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Step 3: Due to the symmetry and spacing of the three grooves:
\begin{itemize}
\item The impressions repeat periodically,
\item The white shapes appear as evenly spaced diamond-like forms,
\item The pattern must be consistent along the rolling direction.
\end{itemize}
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Step 4: Comparing all options:
\begin{itemize}
\item A: Incorrect spacing and alignment of impressions.
\item B: Correct repetition, orientation, and spacing of the diamond-shaped impressions — valid.
\item C: Mismatch in shape continuity.
\item Option D: Rounded shapes are inconsistent with V-shaped cuts.
\end{itemize}
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Final Answer:
\[
\boxed{B}
\]
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