Compare a micrometer and a caliper in terms of use and precision.

• A. A micrometer measures external and depth with lower precision
• B. A caliper has higher precision than a micrometer
• C. A micrometer measures small external dimensions with higher precision; a caliper measures external/internal dimensions and depth with moderate precision
• D. A micrometer can measure inside holes

Answer: (C)

Micrometers and calipers differ in precision and what they measure. A micrometer is built for very small external dimensions and offers higher precision, typically to thousandths of an inch or hundredths of a millimeter. A caliper is more versatile: it can measure external dimensions, internal dimensions with the inside jaws, and depth with a depth rod, but its precision is more moderate.

So the statement that micrometers measure small external dimensions with higher precision, while a caliper measures external/internal dimensions and depth with moderate precision, best describes how these tools are used in practice. The other descriptions mix up depth capability or misstate precision, so they don’t fit as well.