Question

Which of the following is incorrect about micrometer?

(a) Thimble and barrel should have a dull finish

(b) Total travel of the measuring spindle is called measuring range

(c) Graduated surface diameter of barrel should be 5 mm

(d) Screw has 10 or 20 threads per cm

This question was posed to me in semester exam.

My question is taken from Micrometers topic in chapter Linear Measurements of Engineering Metrology

Answer 1

The correct answer is (c) Graduated surface diameter of barrel should be 5 mm

For explanation I would say: Thimble and barrel should have a dull finish for ease of reading. Graduated surface diameter of the barrel should not be less than 10 mm.