Which of the following physical quantities can be measured by a ruler, a vernier caliper, and a micrometer? Is it (A) mass, (B) time, or (C) length?
Let’s think about what kind of tools we would need in order to measure mass. The units of mass are grams and kilograms. And the tools that we’d use to measure these are balances and scales, not rulers, calipers, or micrometers. So (A) cannot be our answer.
Now let’s look at measuring time. Time can be measured in seconds, minutes, hours, days, months, years, and so on. The tools used for measuring time include hourglasses, stopwatches, and, on a longer scale, clocks and even calendars. You do not measure time with a ruler, caliper, or micrometer, so it cannot be (B).
The physical quantity that can be measured by a ruler, a vernier caliper, and a micrometer is length. The units of length, meters, centimeters, and millimeters, are all measured by the ruler, vernier caliper, and a micrometer.