Question

Diameter measurements should be recorded in cm and to the nearest multiple of ______________ in CGS system

• A. 2.0 cm
• B. 2.0 mm
• C. 5.0 mm
• D. 10.0 mm

Hint:

While we use "Diameter Classes" (like 20-30 cm) for management, the "Reading" on the instrument should always be as precise as $0.2$ cm ($2$ mm) to maintain scientific accuracy.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
This question relates to the standard precision requirements for recording tree diameter in forest inventories and research using the metric system.

Step 2: Detailed Explanation:

• In standard Indian forest practice (CGS/Metric system), diameter is measured at breast height ($1.37$ m).

• For general working plan inventories, trees are often grouped into 2 cm or 10 cm diameter classes.

• However, for research purposes and individual tree measurements, calipers or diameter tapes are read with high precision.

• The standard precision required is often to the nearest $0.2$ cm, which is equivalent to $2.0$ mm.

• This level of precision is necessary to detect incremental changes in growth over short periods.

Step 3: Final Answer: Diameter measurements should be recorded to the nearest multiple of 2.0 mm.