(A) Vernier callipers with 20 divisions on sliding scale, coinciding with 19 main scale divisions <br> (B) A screw gauge of pitch 1 mm and 100 divisons on the circular scale <br> (C) An optical instrument that can measure length to within a wavelength of light Out of A, B and C the most precise devide for measuring length is
Apne doubts clear karein ab Whatsapp par bhi. Try it now.
A device with minimum count is the most suitable to measure length. (a) Least count of vernier callipers = 1 standard division (SD) – 1 vernier division (VD) <br> =`1-9/10=1/10=0.01 cm ` <br> (b) Least count of screw gauge =`("Pitch")/("number of divisions")` <br> `=1/1000=0.001 cm ` <br> (c) Least count of an optical device =wavelength of lifhg ~ `10^(-5) cm` <br> =0.00001 cm <br> Hence, it can be inferred that an optical instrument is the most suitable device to measure length.