CDT Drafting & Design Principles & Techniques 3 — Questions and Answers
Question 1: What is the purpose of an auxiliary view in technical drawing?
- To show the true shape of an inclined surface not visible in standard views (Correct answer)
- To provide an isometric representation of the object
- To replace the front view when it is unclear
- To show hidden features behind the object
Correct answer: To show the true shape of an inclined surface not visible in standard views
An auxiliary view is projected onto a plane parallel to the inclined surface, revealing its true size and shape.
Question 2: In multiview drawing, which view is typically positioned directly below the front view?
- Top view
- Bottom view (Correct answer)
- Right side view
- Auxiliary view
Correct answer: Bottom view
In third-angle projection (US standard), the bottom view is placed below the front view, showing what is seen looking up at the object.
Question 3: What is the function of 'crosshatching' in a section view?
- To indicate the material cut by the cutting plane (Correct answer)
- To show hidden lines beyond the cut surface
- To label different parts of an assembly
- To indicate a surface finish requirement
Correct answer: To indicate the material cut by the cutting plane
Section lines (crosshatching) are drawn at 45° on cut surfaces to distinguish solid material from voids and indicate that the surface was cut.
Question 4: Which geometric relationship is true of two lines that are 'parallel' in space?
- They never intersect and remain equidistant (Correct answer)
- They intersect at exactly one point
- They lie in the same plane and intersect at 90°
- They are skew if they appear parallel in one view
Correct answer: They never intersect and remain equidistant
Parallel lines maintain a constant distance from each other and never intersect, regardless of how far they are extended.
Question 5: When dimensioning a drawing, the 'unidirectional' system means:
- All dimension numerals are read from the bottom of the sheet (Correct answer)
- Dimension numerals are aligned with their dimension lines
- Numerals run parallel to the object's longest axis
- Each dimension is placed in a separate view
Correct answer: All dimension numerals are read from the bottom of the sheet
In the unidirectional system, all dimension values are oriented to be read from the bottom of the drawing sheet, regardless of dimension line direction.
Question 6: A 'phantom line' (long-short-short-long dash pattern) is used to show:
- Alternate positions of moving parts or adjacent parts not part of the object (Correct answer)
- The cutting plane location for a section view
- A repeated detail or symmetry axis
- The outline of a removed section
Correct answer: Alternate positions of moving parts or adjacent parts not part of the object
Phantom lines indicate alternate positions of moving parts, repeated features, or the outlines of adjacent parts for reference.
Question 7: In technical drawing, 'foreshortening' occurs when:
- A line or surface appears shorter than its true length because it is not parallel to the projection plane (Correct answer)
- A dimension is accidentally omitted from a view
- A circular feature is projected as an ellipse in an isometric view
- Scale is applied incorrectly to a drawing
Correct answer: A line or surface appears shorter than its true length because it is not parallel to the projection plane
Foreshortening is the visual shortening of a feature when it is inclined to the projection plane, making it appear shorter than its actual length.
CDT Drafting & Design Principles & Techniques 3
What is the purpose of an auxiliary view in technical drawing?