🔍 Key Concepts

• Understand how to read a vernier micrometer caliper: combine the sleeve (barrel) reading with the thimble (rotating) reading and then add any vernier fraction. • Identify how many whole thousandths of an inch are shown on the main scale before the zero of the thimble passes it. • Find which vernier line exactly lines up with a line on the thimble to determine the ten‑thousandths (0.0001 in) value.

💭 Think About

• First, look at figure D and decide what the base reading is on the main (sleeve) scale, just before the thimble zero mark. Which hundredths and thousandths marks are clearly passed? • Next, read the thimble scale: which line on the thimble is exactly aligned with the reference line on the sleeve? Convert that to thousandths of an inch. • Finally, check the vernier scale: which vernier division lines up best with a thimble line, and how many ten‑thousandths of an inch does each vernier division represent?

✅ Before You Answer

• Be sure you are counting from the correct zero line on each scale (sleeve, thimble, and vernier). • Confirm that you are not double‑counting the last visible mark on the sleeve; only include marks that the thimble zero has clearly passed. • After adding sleeve + thimble + vernier readings, confirm that your total matches one of the answer choices to the fourth decimal place.