Technical Drawing JAMB Past Questions And Answers (Objectives and Theory)
Section A: Multiple Choice Questions
Which of the following types of lines is used to represent visible edges or outlines of objects in technical drawings?
a) Centerline
b) Hidden line
c) Object line
d) Dimension line
Answer: c) Object line
What does the abbreviation “ISO” stand for in technical drawing standards?
a) International Standards Organization
b) Industrial Standards Organization
c) Internal Standards Organization
d) Institute of Standards Organization
Answer: a) International Standards Organization
Which type of projection is commonly used in technical drawings to represent three-dimensional objects on a two-dimensional plane?
a) Isometric projection
b) Orthographic projection
c) Perspective projection
d) Oblique projection
Answer: b) Orthographic projection
What is the purpose of dimension lines in technical drawings?
a) To define the size and shape of objects
b) To indicate the location of holes
c) To specify the material of objects
d) To provide instructions for assembly
Answer: a) To define the size and shape of objects
Which of the following drafting tools is used to draw circles and arcs?
a) T-square
b) Compass
c) French curve
d) Protractor
Answer: b) Compass
What does the term “scale” refer to in technical drawing?
a) The ratio of the drawing’s size to the actual size of the object
b) The type of pencil used for drawing
c) The angle of projection used
d) The thickness of lines in the drawing
Answer: a) The ratio of the drawing’s size to the actual size of the object
Which of the following types of lines is used to represent the axes of symmetry in technical drawings?
a) Phantom line
b) Extension line
c) Construction line
d) Centerline
Answer: d) Centerline
What does the abbreviation “CAD” stand for in the context of technical drawing?
a) Computer-Aided Design
b) Computer-Assisted Drawing
c) Centralized Architecture Design
d) Computerized Artistic Drafting
Answer: a) Computer-Aided Design
Which type of projection is characterized by the use of vanishing points to create the illusion of depth?
a) Isometric projection
b) Orthographic projection
c) Perspective projection
d) Oblique projection
Answer: c) Perspective projection
What does the term “tolerance” refer to in technical drawings?
a) The maximum permissible deviation from a specified dimension
b) The number of copies to be made of a drawing
c) The degree of accuracy required in a drawing
d) The amount of detail included in a drawing
Answer: a) The maximum permissible deviation from a specified dimension
Section B: Theory Questions
Explain the importance of orthographic projection in technical drawing and provide an example.
Answer: Orthographic projection is essential in technical drawing as it allows for the accurate representation of three-dimensional objects on a two-dimensional plane. It provides multiple views of an object, including front, top, side, and bottom views, which aid in understanding its shape, size, and dimensions. For example, orthographic projection is used in architectural drawings to depict floor plans, elevations, and sections of buildings.
Discuss the role of line types and line weights in technical drawings.
Answer: Line types and line weights play crucial roles in conveying information in technical drawings. Different types of lines, such as object lines, hidden lines, centerlines, and dimension lines, are used to represent various features of objects. Line weights, which refer to the thickness or darkness of lines, help distinguish between different elements and emphasize important details. For example, thicker lines may be used to highlight prominent features or boundaries, while thinner lines may indicate hidden or less significant elements.
Describe the purpose of section views in technical drawings and provide an example.
Answer: Section views are used in technical drawings to show the internal structure of objects by cutting them along imaginary planes and removing a portion to reveal their interior details. Section views provide clarity and insight into the construction, assembly, and functionality of complex objects. For example, a section view may be used in engineering drawings to illustrate the internal components of a machine or the cross-section of a building.
Explain the concept of geometric dimensioning and tolerancing (GD&T) and its significance in technical drawings.
Answer: Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating the allowable variations in form, size, orientation, and location of features on a part or assembly. It uses symbols, dimensions, and tolerances to specify the requirements for manufacturing and inspection. GD&T ensures consistency, accuracy, and interchangeability of parts, leading to improved quality, reduced costs, and enhanced functionality of products.
Discuss the advantages and limitations of computer-aided design (CAD) software in technical drawing.
Answer: CAD software offers numerous advantages in technical drawing, including increased productivity, accuracy, and flexibility. It allows for easier editing, sharing, and storage of drawings, as well as the creation of complex geometries and precise measurements. However, CAD software also has limitations, such as the initial cost of software and training, the need for specialized hardware, and potential compatibility issues with legacy systems. Additionally, CAD drawings may lack the tactile feedback and artistic expression of hand-drawn sketches.
