🔍 Key Concepts

• Micrometer Vernier scale and how it increases precision beyond the standard micrometer thimble scale • Typical smallest divisions on a standard inch micrometer (without Vernier) • Relationship between thousandths of an inch (0.001") and ten-thousandths of an inch (0.0001")

💭 Think About

• What is the usual smallest reading you can get from a standard micrometer without a Vernier scale? • Does adding a Vernier scale usually make the instrument read coarser or finer? By about how much? • Which answer choice represents a significantly finer (smaller) increment than a thousandth of an inch, rather than a larger one?

✅ Before You Answer

• Confirm which options are smaller than 0.001 inch (more precise) and which are larger (less precise). • Convert "one fortieth of an inch" to a decimal to see if it is finer or coarser than thousandths of an inch. • Recall that a Vernier scale is used to increase resolution, so the correct option must represent a smaller increment than the standard micrometer reading.