Question

What is the unit of the representative fraction?

• A. Centimeter
• B. Meter
• C. Kilometer
• D. There is no unit

Hint:

The representative fraction (e.g., 1:100) is a unitless ratio, comparing drawing measurements to actual measurements.

Answer 1

The Correct Option is D

Defining representative fraction
Step 1: The representative fraction (RF) in technical drawing is the ratio of a distance on a drawing to the corresponding distance in reality (e.g., 1:100).
Analyzing units
Step 2: Since RF is a ratio of two lengths (e.g., 1 cm on the drawing to 100 cm in reality), the units cancel out, making it dimensionless.
Evaluating options
Step 3: Analyze the options:
- (A) Centimeter: Incorrect, as RF is unitless.
- (B) Meter: Incorrect, as RF is unitless.
- (C) Kilometer: Incorrect, as RF is unitless.
- (D) There is no unit: Correct, as RF is a dimensionless ratio.
Thus, the correct answer is (D).