Engineering Graphics and Design (EGD) Theory Review

Comprehensive Question and Answer flashcards covering the EGD Theory Bundle for grades 10 to 12, including drawing principles, mechanical, civil, and geometric constructions.

What is the primary purpose of Engineering Graphics and Design (EGD)?

To teach internationally acknowledged principles with academic and technical applications, enabling learners to interpret and produce drawings within Mechanical Technology, Civil Technology, and Electrical Technology contexts.

What is the specific use of an A-type line quality in EGD?

The darkest line used for borders, title/name blocks/panels, outlines, visible parts, answers of loci, projection symbols, and tables.

According to general lettering requirements, what are the heights for labels and titles?

Labels and dimensions must be $3\,mm$ high, and titles must be $5\,mm$ high.

In dimensioning, what is the rule for placing the symbol for diameter ($\varnothing$)?

The symbol must ALWAYS be placed before the number, for example: $\varnothing 12$.

How is a radius symbol (R) correctly used in circles?

It represents the distance from the centre point to the edge and is ALWAYS placed before the number, for example: $R6$.

What is the difference between an orthographic grid and a pictorial grid in freehand drawing?

An orthographic grid is used for single or multi-view drawings, while a pictorial grid is used for $3D$ drawings.

What is a 'Perpendicular bisector'?

A perpendicular line that divides another line exactly in half.

Define a 'Tangent line' as used in geometrical construction.

A straight line that touches a circle at only one single point.

How is a 'Full-size scale' defined in EGD?

An accurately proportioned drawing where the ratio compares the drawing to be exactly the same size as the real-life object ($1:1$).

Describe the positioning of views in First-angle orthographic projection.

The object is placed in the first quadrant, normally displaying the front, top, and left views where the projection plane is located between the viewport and the object.

In mechanical drawing, what does the abbreviation 'PCD' stand for?

Pitch Circle Diameter.

Which two mechanical parts are classified as 'Parts that may never be sectioned'?

Washer and Nuts.

What are the characteristics of 'Isometric lines'?

Lines that fall on the main angles of $90^{\circ}$ and $30^{\circ}$ whose lengths can be measured directly onto the drawing.

In descriptive geometry, when is a line viewed in its 'true length'?

When the line is viewed perpendicular ($90^{\circ}$) to the observer's line of sight.

Define a 'Right regular solid' according to physical properties.

A solid where the axis is perpendicular to and in the centre of its base (Right) and all base sides are equal in length with equal interior angles (Regular).

What is the standard thickness for load-bearing (outside) and non-load-bearing (inside) walls in civil drawing?

Load-bearing walls are $220\,mm$ thick and non-load-bearing walls are $110\,mm$ thick.

According to National Building Regulations, what color represents 'New Masonry' on floor plans?

Red.

What are the common abbreviations for 'Natural Ground Level' and 'Finished Floor Level'?

NGL and FFL.

Define 'Station Point (SP)' in the context of perspective drawing.

The position (point) and orientation from which the observer views an object.

What is a 'Vanishing Point (VP)'?

The point of convergence on the horizon line between lines extending from the foreground to the background.

In cam loci, what are the three movements typically defined in a displacement graph?

Rise (follower moves up), Dwell (follower stays at same height), and Fall (follower moves down).

Compare 'Reciprocating motion' and 'Oscillating motion' in mechanisms.

Reciprocating motion is a repeated straight-line motion moving back and forth or up and down, whereas oscillating motion is a curved or arc-shaped movement swinging back and forth on an axis without completing a full circle.