What type of line is primarily used to indicate an alternate position of a moving part?

• A. Phantom Line
• B. Dashed Line
• C. Hidden Line
• D. Construction Line

Answer: (A)

A phantom line is used primarily to indicate alternate positions of a moving part. This type of line typically consists of a long dash followed by two short dashes and is essential in technical drawings and blueprints. By employing a phantom line, designers can effectively illustrate where a part will move or its various positions throughout its range of motion, without obscuring the details of the actual part itself. This allows anyone interpreting the drawing to understand the intended movement and functionality clearly.

In contrast, each of the other line types serves different purposes. Dashed lines often represent hidden edges or boundaries that are not visible in the particular view of a drawing but do exist in three-dimensional space. Hidden lines indicate edges that are obscured and, thus, are not seen directly. Construction lines are used as guides to help with layout and measurements but do not convey the same information about the motion of parts.