Which of the following is the most precise device for measuring length (i) a vernier calipers with 20 divisions on the sliding scale (ii) a screw gauge of pitch 1mm and 100 divisions on the circular scale (iii) an optical instrument that can measure length to within a wavelength of light?

Which of the following is the most precise device for measuring length

1.	Which of the following is the most precise device for measuring length (i) a vernier calipers with 20 divisions on the sliding scale (ii) a screw gauge of pitch 1mm and 100 divisions on the circular scale (iii) an optical instrument that can measure length to within a wavelength of light?
Answer» VERNIER calipers Screw guage Optical instrument All the above Answer :C