Average = (6.25 + 6.27 + 6.26) ÷ 3 = 18.78 ÷ 3 = 6.26 mm Section C Answers 10. False – The thimble typically has 50 divisions , each = 0.01 mm. Some have 100 (0.001 mm resolution), but standard school ones use 50.
– The ratchet slips when the correct pressure is applied, preventing damage to the screw or object.
– Human hair is ~0.02–0.2 mm thick. A 0.01 mm resolution micrometer can measure it, though carefully. Quick Reference: Common Mistakes | Mistake | Correction | |---------|-------------| | Forgetting the half mm | Always check the short line above the main scale. | | Misreading thimble (e.g., 32 as 0.32) | That’s correct, but remember: 32 = 0.32 mm. | | Ignoring zero error | Always check and subtract/add before final answer. | | Parallax error | Read the thimble alignment straight-on, not at an angle. |
The ratchet prevents over-tightening and damage. (T / F)
