What precision measuring instrument is used to determine the thickness or diameter of objects like stems or seeds?

What precision measuring instrument is used to determine the thickness or diameter of objects like stems or seeds?

• A. Hand Lens
• B. Spectrophotometer
• C. Calipers
• D. Micropipette

Answer: (C)

Calipers are used to determine thickness or diameter because they provide a direct, precise measurement of external dimensions. With the jaws you clamp around the object for outside measurements, and the scale (vernier, dial, or digital) gives a readout to small increments, which is ideal for stems or seeds where small size differences matter. You can measure width across the widest point or even the depth with the depth rod. The other tools don’t fit this task: a hand lens only magnifies without giving a measurement, a spectrophotometer analyzes light properties rather than physical size, and a micropipette is for measuring very small volumes of liquid.

Calipers are used to determine thickness or diameter because they provide a direct, precise measurement of external dimensions. With the jaws you clamp around the object for outside measurements, and the scale (vernier, dial, or digital) gives a readout to small increments, which is ideal for stems or seeds where small size differences matter. You can measure width across the widest point or even the depth with the depth rod. The other tools don’t fit this task: a hand lens only magnifies without giving a measurement, a spectrophotometer analyzes light properties rather than physical size, and a micropipette is for measuring very small volumes of liquid.