AutoCAD is the most widely used CAD software for civil, mechanical, electrical and architectural drafting. These AutoCAD interview questions cover commands, coordinates, layers and drawing setup for freshers, then blocks, dimensions, layouts, xrefs, 3D modelling and drawing standards for experienced draughtsmen and engineers.
30 questions · Updated
Fundamentals, definitions and simple scenarios. Good for freshers and warm-ups.
AutoCAD is computer-aided design software from Autodesk for creating precise 2D drawings and 3D models. Civil and structural engineers use it for plans, sections and site layouts, mechanical engineers for part and assembly drawings, electrical engineers for wiring and panel layouts, and architects and interior designers for floor plans and elevations.
Absolute coordinates are measured from the origin (0,0), typed as 100,50.
Relative coordinates are measured from the last point, typed as @100,50.
Polar coordinates use distance and angle from the last point, typed as @100<45.
The World Coordinate System is fixed, while a User Coordinate System (UCS) can be moved and rotated to make drawing easier.
LINE (L), POLYLINE (PL), CIRCLE (C), RECTANGLE (REC), TRIM (TR), EXTEND (EX), OFFSET (O), MIRROR (MI), COPY (CO), MOVE (M), ROTATE (RO), SCALE (SC), FILLET (F), CHAMFER (CHA), ARRAY (AR), HATCH (H), EXPLODE (X) and MATCHPROP (MA). Object snaps (F3), ortho (F8) and polar tracking (F10) help draw accurately.
The UNITS command sets the length type (decimal, architectural or engineering), precision, angle type and insertion units, such as millimetres for mechanical drawings or metres for site plans.
LIMITS sets the drawing area boundaries, which matters less today because model space is unlimited.
Starting from the right template sets units correctly from the beginning.
Object snaps (OSNAP, toggled with F3) let you pick exact points on existing objects, such as endpoint, midpoint, centre, intersection, perpendicular, tangent, quadrant, nearest and extension.
Running snaps stay on, and you can override them for one pick by typing the snap name or using Shift+right-click.
Accurate snapping is essential for precise drawings.
The HATCH command fills closed areas with patterns, solid fills or gradients to show materials or sections, such as concrete, brick, earth or steel.
You pick points inside boundaries or select objects, set the pattern scale and angle, and use annotative hatches so pattern scale suits each viewport.
Associative hatches update when boundaries change.
Single-line text (TEXT or DTEXT) creates separate text objects for each line, which suits short labels.
Multiline text (MTEXT) creates a paragraph inside a box with word wrap, formatting, columns, bullets and special symbols, which suits notes and specifications.
Text styles define fonts and sizes, and annotative text keeps sizes correct at different scales.
A LINE creates separate segments, each a separate object.
A polyline (PLINE) is a single object made of connected line and arc segments, which can have width, be closed, measured for area and length easily, offset as one, and used as hatch boundaries.
PEDIT and JOIN convert lines into polylines.
Selecting an object shows grips, small squares at key points, which you can drag to stretch, move, rotate, scale or mirror the object quickly, with multi-functional grip menus for polylines. The Properties palette (Ctrl+1) shows and edits all properties of selected objects, such as layer, colour, linetype, dimensions and text content, including for many objects at once.
ZOOM changes the view magnification, with options such as Extents (show everything), Window and Previous, usually done with the mouse wheel; double-clicking the wheel zooms to extents.
PAN moves the view without changing magnification.
REGEN recalculates the drawing's display from the database, which fixes display problems such as circles appearing as polygons.
From a layout, use the PLOT command or Page Setup Manager to choose the printer or PDF plotter, paper size, plot area (usually the layout), scale (1:1 on layouts), plot style table (CTB or STB) to control lineweights and colours, and orientation. Saving page setups ensures consistent output, and Publish plots many sheets at once.
Applied problems, trade-offs and questions about your own projects.
Layers organise objects by type, such as walls, doors, dimensions, text, electrical and furniture, each with its own colour, linetype and lineweight.
You can turn layers on or off, freeze or lock them, control printing and manage them with the Layer Properties Manager.
Following a company's layer standard keeps drawings consistent and easy for others to use.
A block is a group of objects saved as one named object that can be inserted many times, such as a door, window or bolt.
Editing the block definition updates every instance and keeps file size small.
Dynamic blocks add parameters and actions, such as stretch, flip or a list of sizes, so one block can represent many variations.
Attributes add text data, such as part numbers, that can be extracted to a table.
Model space is where you draw everything at full size (1:1).
Paper space layouts represent the printed sheet, with a title block, and use viewports to show parts of the model at a chosen scale, such as 1:100.
One model can have several layouts at different scales.
Annotative objects keep text and dimensions the right size at each scale.
I set up a dimension style matching the company standard with text height, arrow type, units and precision, and use annotative scaling. I use linear, aligned, angular, radius, diameter, baseline and continuous dimensions as needed, dimension from datums, avoid duplicate dimensions, and keep dimensions associative so they update when geometry changes.
Annotative objects, such as text, dimensions, hatches, multileaders and blocks, adjust their size automatically to the scale of each viewport, so text appears at the same printed height whether the viewport is at 1:50 or 1:100. Objects can support several annotation scales, and annotation visibility shows only those matching the current scale.
Attributes are text fields attached to blocks that store information, such as a door type, equipment tag or part number, which users fill in when inserting the block. DATAEXTRACTION pulls block counts, attribute values and object properties into a table in the drawing or an Excel file, which is used for schedules and bills of materials.
Tool palettes (Ctrl+3) store frequently used blocks, hatches and commands with preset properties, such as layer and scale, for quick drag-and-drop use.
DesignCenter (Ctrl+2) browses other drawings to reuse their blocks, layers, text styles, dimension styles and layouts.
Both help teams follow standards and avoid redrawing content.
Geometric constraints define relationships between objects, such as parallel, perpendicular, tangent, coincident, horizontal and equal.
Dimensional constraints control sizes and can use formulas and parameters, such as setting a length to twice a width.
Changing a parameter updates the geometry automatically, which suits design variations.
Plain AutoCAD suits general 2D drafting and detailing.
Civil 3D, built on AutoCAD, models terrain surfaces, alignments, profiles, corridors, grading and pipe networks for roads and infrastructure.
Revit is a BIM tool for buildings, where walls, floors and systems are intelligent objects and plans, sections and schedules are generated from one model.
Projects often combine them.
Layer states save the on, off, frozen, colour and other settings of all layers so you can switch between configurations, such as an electrical view and a furniture view, with one click. Layer filters show only certain layers in the Layer Properties Manager, based on names or properties (property filters) or chosen layers (group filters), which helps in drawings with hundreds of layers.
Raster images, PDFs and DWF or DGN files can be attached as underlays to trace over or reference, such as a site photo or a consultant's PDF drawing, with snapping to PDF geometry.
XCLIP or the clip commands show only part of a reference.
Attached references are managed in the External References palette, with relative paths for sharing.
System design, deep internals, leadership and tough follow-ups.
An xref links another drawing file into the current one without copying its content, for example an architectural plan referenced into structural and electrical drawings.
When the source is updated, every drawing that references it updates on reload.
Xrefs keep files small, allow teams to work in parallel, and are managed through the External References palette with relative paths.
In the 3D Modeling workspace I create solids with commands such as EXTRUDE, REVOLVE, SWEEP, LOFT and PRESSPULL, combine them with UNION, SUBTRACT and INTERSECT, and add details with FILLETEDGE and CHAMFEREDGE.
I view them with visual styles and the ViewCube, and generate 2D drawings from the model with VIEWBASE.
For complex parametric parts, dedicated tools such as SolidWorks, Inventor or Revit are more suitable.
I start from company templates (DWT) with standard layers, text styles, dimension styles and title blocks, and use the CAD Standards checker.
Before issue I purge unused items, audit and recover errors, check scale, dimensions and spelling, confirm the revision table, and plot to PDF with correct plot styles (CTB or STB).
Sheet Set Manager helps manage large drawing sets.
AutoLISP routines automate repetitive drafting and create custom commands, script files (.scr) run sequences of commands across many drawings, action macros record steps, and the .NET and ObjectARX APIs build more complex add-ins.
Tools such as the batch plot (Publish) and Sheet Set Manager also save time.
Shared routines should be tested and documented.
External references let each discipline work on its own drawing while seeing the others, DWG Compare highlights differences between versions, Shared Views publish views for comments in a browser, Autodesk Docs and Autodesk Construction Cloud manage versions and reviews, and eTransmit packages a drawing with all its references, fonts and plot styles for sending.
For vector PDFs, PDFIMPORT converts geometry, text (with text recognition) and hatches into AutoCAD objects, which then need cleaning, layer organisation and scale checking. Scanned drawings are raster images, so they are attached, scaled using known dimensions and traced, or converted with raster-to-vector software, always checking critical dimensions.
CAD produces drawings made of lines, arcs and text that represent a design, so each view is drawn separately and must be updated manually.
BIM, with tools such as Revit, creates an intelligent 3D model of building elements with data, from which plans, sections, schedules and quantities are generated and stay consistent.
BIM supports clash detection, coordination and facility management, while CAD is still widely used for detailing.
Use AUDIT to find and fix errors, RECOVER to open damaged files, PURGE to remove unused blocks, layers and styles (including registered applications), OVERKILL to remove duplicate and overlapping objects, and remove unnecessary proxy objects and annotation scales.
Inserting the drawing into a new file (WBLOCK) can also clean it.
Regular backups and autosave protect against data loss.
See all Mechanical Engineer interview questions, covering Thermodynamics, Strength of Materials, Fluid Mechanics, Heat Transfer, Manufacturing Processes and more.