Matching Instrument Precision to Internal Diameter Scales

Steps:

• Identify measurement sizes: wire internal diameter ~1 mm (small, needs high precision); pipe internal diameter ~2 cm or 20 mm (larger, moderate precision).
• Recall instrument capabilities: micrometers measure to 0.01 mm accuracy, ideal for small internals like wires using inside micrometers.
• For pipe's 20 mm internal, inside micrometers (with extensions) provide precise measurement without calipers' lower resolution (~0.1 mm).
• Select micrometers for both to ensure consistent high accuracy over the given scales.

Why D is correct:

• Micrometers are designed for precise internal diameter measurements across small (1 mm) to moderate (20 mm) ranges, per standard metrology definitions.

Why the others are wrong:

• A: Calipers lack precision for 1 mm wire internals (resolution too coarse).
• B: Calipers unsuitable for precise 1 mm wire measurement.
• C: Calipers less accurate than micrometers for 20 mm pipe internals.

Final answer: D