🔍 Key Concepts

• Micrometer reading basics: Add the sleeve (barrel) reading to the thimble reading, and if present, include the vernier reading for ten‑thousandths (0.0001 in). • On a 0–1 inch micrometer, each numbered division on the sleeve usually equals 0.100 in, each short line 0.025 in, and each line on the thimble equals 0.001 in. • A reading of 0.4815 in means 0.400 in + 0.080 in + 0.0015 in, so the sleeve, thimble, and (if used) vernier must together add up to this value.

💭 Think About

• First, decide what the sleeve (barrel) must show: up to what full 0.025 in mark has the thimble passed for a total just under 0.482 in? • Next, determine where the thimble scale should be: which figure shows a thimble position that adds about 0.006–0.007 in beyond the sleeve reading? • If there is a vernier for 0.0001 in increments, which figure shows the vernier line matching the thimble so that the extra 0.0005 in is accounted for?

✅ Before You Answer

• Identify which figure has the sleeve reading between 0.475 in and 0.500 in (just under the 0.5 inch mark). • Check that the thimble scale is around 6–7 thousandths beyond that sleeve position (around 0.006–0.007 in). • Confirm that any vernier alignment would add the remaining 0.0005 in needed to reach 0.4815 in, and eliminate any figure whose combined reading is clearly closer to another value (like ~0.46, ~0.49, or ~0.50).