BME Engineering Drawing and CAD 2 — Questions and Answers
Question 1: In CAD, parametric modeling means:
- Models are created from scanned images
- Model geometry is driven by defined parameters and constraints (Correct answer)
- Only 2D drawings are created
- Models cannot be modified after creation
Correct answer: Model geometry is driven by defined parameters and constraints
Parametric modeling ties geometry to design parameters (dimensions and constraints), so changing a parameter automatically updates the entire model.
Question 2: A datum in GD&T is:
- A manufactured surface
- A theoretically exact point, axis, or plane used as a reference (Correct answer)
- A tolerance zone
- A surface finish specification
Correct answer: A theoretically exact point, axis, or plane used as a reference
A GD&T datum is a theoretically perfect geometric reference (point, line, or plane) established from actual part features to measure other geometric tolerances.
Question 3: Which line type represents the axis of symmetry in engineering drawings?
- Thick continuous line
- Thin dashed line
- Long chain (dash-dot) line (Correct answer)
- Zigzag line
Correct answer: Long chain (dash-dot) line
A centerline (long chain or dash-dot-dash line) indicates axes of symmetry, center points, and paths of motion in engineering drawings.
Question 4: In ASME Y14.5 GD&T, the Maximum Material Condition (MMC) modifier means:
- The part has the least material
- The feature contains the most material within its tolerances (Correct answer)
- Material cost is maximized
- The feature is at nominal size
Correct answer: The feature contains the most material within its tolerances
MMC refers to the condition where a feature of size contains the maximum amount of material — largest shaft diameter or smallest hole diameter within tolerance.
Question 5: An isometric view is a type of:
- Orthographic projection
- Pictorial (axonometric) projection (Correct answer)
- Perspective projection
- Section view
Correct answer: Pictorial (axonometric) projection
Isometric projection is an axonometric (pictorial) drawing where all three axes are equally inclined to the projection plane at 30°, giving equal foreshortening.
Question 6: Surface finish (roughness) on a drawing is indicated by:
- Dashed boundary lines
- A check mark symbol (√) with Ra value (Correct answer)
- Cross-hatching
- Wavy lines
Correct answer: A check mark symbol (√) with Ra value
Surface texture is specified using the surface finish symbol (√) with roughness value Ra (arithmetic average) per ASME B46.1 standards.
BME Engineering Drawing and CAD 2
In CAD, parametric modeling means: