OIT Blueprint Reading and Technical Drawing 1 — Questions and Answers
Question 1: What does a hidden line (dashed line) represent in a technical drawing?
- A surface that is visible from the current view
- An edge or surface that is not visible from the current view (Correct answer)
- The centerline of a symmetrical object
- A cutting plane for a section view
Correct answer: An edge or surface that is not visible from the current view
Hidden lines (dashed lines) represent edges or surfaces that exist in the object but cannot be seen from the current viewing angle.
Question 2: On a blueprint, the scale notation '1:2' means which of the following?
- 1 unit on the drawing equals 2 units in real life (Correct answer)
- 2 units on the drawing equal 1 unit in real life
- The drawing is full size
- The drawing has no defined scale
Correct answer: 1 unit on the drawing equals 2 units in real life
A scale of 1:2 means every 1 unit measured on the drawing represents 2 units in actual size, making the drawing half of real size.
Question 3: What is the primary purpose of a title block on a technical drawing?
- To show the front view of the object
- To list all materials required for fabrication
- To provide key identification and reference information about the drawing (Correct answer)
- To indicate the revision history only
Correct answer: To provide key identification and reference information about the drawing
The title block contains critical reference information such as the drawing number, title, scale, date, drafter's name, and revision level.
Question 4: What type of view is created by passing an imaginary cutting plane through an object to reveal its internal features?
- Auxiliary view
- Section view (Correct answer)
- Isometric view
- Elevation view
Correct answer: Section view
A section view (cross-section) reveals interior details by showing the object as if it were cut along a cutting plane, making hidden internal features visible.
Question 5: In technical drawing, what does GD&T stand for?
- General Drawing and Tolerance
- Geometric Dimensioning and Tolerancing (Correct answer)
- Grade, Dimension, and Template
- Global Design and Technology
Correct answer: Geometric Dimensioning and Tolerancing
GD&T (Geometric Dimensioning and Tolerancing) is a system for defining and communicating engineering tolerances and allowable variations in form, fit, and function.
Question 6: Which line type in technical drawing indicates the axis of symmetry or the center of a circular feature?
- Solid thick line
- Dashed thin line
- Chain line (alternating long and short dashes) (Correct answer)
- Phantom line (long dash, two short dashes)
Correct answer: Chain line (alternating long and short dashes)
Centerlines are drawn as chain lines (alternating long and short dashes) and identify axes of symmetry, centers of holes, and paths of motion.
Question 7: In third-angle projection (used in North America), where is the front view typically located on the drawing sheet?
- Top-left corner
- Center of the sheet with related views arranged around it (Correct answer)
- Bottom-right corner
- The front view is always the largest view shown
Correct answer: Center of the sheet with related views arranged around it
In third-angle projection, the front (principal) view is placed in the center, with the top view above it, the right-side view to the right, and the left-side view to the left.
OIT Blueprint Reading and Technical Drawing 1
What does a hidden line (dashed line) represent in a technical drawing?