Question 492General Subjects - Assistant Engineer

The correct answer is C) one ten thousandth of an inch. A micrometer is a precision measuring instrument that can measure to extremely small increments, down to one ten thousandth of an inch (0.0001 inch). Therefore, if a micrometer were opened to a distance of 0.0001 inch, the reading would be one ten thousandth of an inch. The other options are incorrect because: A) one millionth of an inch is too small (one millionth is 0.000001 inch). B) ten millionths of an inch is too small (ten millionths is 0.00001 inch). D) ten one thousandths of an inch is too large (ten one thousandths is 0.01 inch).