In technical drawing, what is the scale factor for a full-scale drawing? Choose the correct expression that indicates the drawing size equals the actual object size.

Introduction / Context:
Scale communicates the relationship between the drawing and the real object. Reading or setting scale correctly prevents manufacturing errors and ensures that dimensions, when plotted, maintain intended clarity and tolerances.

Given Data / Assumptions:

• We are asked specifically for “full scale.”
• Conventional scale notation uses drawing:object format.
• Units on both sides of the ratio are the same and cancel (unitless ratio).

Concept / Approach:

A full-scale drawing depicts the object at its true size on the sheet or screen. The standard notation is 1:1, meaning 1 unit on the drawing equals 1 unit on the object (millimeters to millimeters, inches to inches, etc.). Other common scales reduce or enlarge size (for example, 1:2 half-size, 2:1 double-size).

Step-by-Step Solution:

Verification / Alternative check:

Drafting standards in mechanical, civil, and architectural fields agree that 1:1 denotes full scale. CAD templates often default to full scale in model space.

Why Other Options Are Wrong:

1:2 is half-size (drawing smaller than actual).

2:1 is double-size (drawing larger than actual).

1:4 is quarter-size (drawing smaller than actual).

Common Pitfalls:

Mixing up notation (some disciplines write scale as NTS “Not to Scale” when no ratio is intended). Always check title blocks for the chosen scale.

Final Answer:

1:1