Which of the following is the most precise devise for measuring length ? (a) a Vernier callipers
Channel: Doubtnut
Date: 2020-08-02

Which of the following is the most precise devise for measuring length ? (a) a Vernier callipers with 20 divisions on the sliding scals, coindiing with 19 main scale divions (b) a screw gauge of pitch 1mm and 100 divisions on the circular scale (c ) an optical instrument that can measure length to within a wave length of light.