CDT CAD Software & Technology Applications 3 — Questions and Answers
Question 1: What is the purpose of a 'block' in CAD drafting?
- A command that prevents editing of selected objects
- A named reusable symbol or group of objects inserted as a single unit (Correct answer)
- A boundary that restricts drawing area
- A type of hatch pattern for filled regions
Correct answer: A named reusable symbol or group of objects inserted as a single unit
A block is a named collection of objects combined into a single unit that can be inserted multiple times, scaled, rotated, and updated globally throughout a drawing.
Question 2: In parametric CAD modeling, what is a 'constraint'?
- A limitation on file size
- A rule that controls the geometric relationship or dimension of sketch elements (Correct answer)
- A restriction on the number of users accessing a file
- A lock applied to prevent layer editing
Correct answer: A rule that controls the geometric relationship or dimension of sketch elements
Constraints in parametric modeling are rules applied to geometry that define relationships (geometric constraints) or sizes (dimensional constraints), allowing the model to update when parameters change.
Question 3: Which plotting setting in CAD determines how drawing colors translate to printed line weights?
- CTB or STB (plot style table) (Correct answer)
- Layer Properties Manager
- Model Space scale factor
- Page Setup Manager title block
Correct answer: CTB or STB (plot style table)
Plot style tables (CTB for color-dependent, STB for named styles) map drawing colors or object styles to specific lineweights, colors, and screening values on the printed output.
Question 4: What distinguishes a '2.5D' CAD drawing from a true 3D model?
- It uses only two layers
- It represents objects with extruded flat shapes without full volumetric geometry (Correct answer)
- It exports only in DXF format
- It cannot include dimensions
Correct answer: It represents objects with extruded flat shapes without full volumetric geometry
2.5D drawings add height (Z-axis extrusion) to flat 2D shapes but lack true 3D geometry like curved surfaces or compound angles, making them simpler than full solid models.
Question 5: In CAD, what is the primary purpose of using 'paper space' versus 'model space'?
- Model space stores text; paper space stores geometry
- Model space is for drawing at full scale; paper space is for composing multi-view layouts for plotting (Correct answer)
- Paper space is used only for 3D modeling
- Model space supports color; paper space supports only monochrome
Correct answer: Model space is for drawing at full scale; paper space is for composing multi-view layouts for plotting
Model space is where geometry is drawn at full real-world scale, while paper space is used to arrange viewports, add title blocks, and set up the drawing sheet for printing.
Question 6: What does 'associative dimensioning' mean in CAD software?
- Dimensions grouped by object type in a table
- Dimensions that automatically update when the associated geometry is modified (Correct answer)
- A style that links dimensions to a database record
- Dimensions shared between multiple drawings via xref
Correct answer: Dimensions that automatically update when the associated geometry is modified
Associative dimensions are linked to the geometry they measure, so if the object is moved, stretched, or resized, the dimension value updates automatically to reflect the change.
Question 7: Which rendering technique in 3D CAD software calculates how light bounces between surfaces to produce realistic illumination?
- Wireframe rendering
- Hidden line removal
- Ray tracing / global illumination (Correct answer)
- Flat shading
Correct answer: Ray tracing / global illumination
Ray tracing and global illumination algorithms simulate realistic lighting by calculating how photons bounce and interact between surfaces, producing shadows, reflections, and color bleeding.
CDT CAD Software & Technology Applications 3
What is the purpose of a 'block' in CAD drafting?