Which instrument measures the distance between two points?

• A. Ruler
• B. Meter
• C. Caliper
• D. Tape measure

Answer: (C)

Measuring the distance between two points requires a tool that can span the gap and give a precise reading. A caliper does just that: its external jaws grip the two points, and the reading across the scale (often with a vernier or digital display) shows the gap with high accuracy. This makes it especially suited for small, exact distances like the thickness or small separations between features.

Rulers and tape measures can measure distance, but their precision is lower for small gaps and they’re more prone to alignment errors. A meter isn’t an instrument for measuring distance on its own—it’s a unit of length.