Which of the following devices is not used to measure length?
Vernier calliper
Screw gauge
Meter scale
Thermometer
Which of the following measures a small length to a high accuracy : metre rule, vernier callipers, screw gauge ?
The scales - vernier callipers, metre scale and screw gauge has the least counts:
Which of the following is the most precise device for measuring length : (a) a vernier callipers with 20 divisions on the sliding scale (b) a screw gauge of pitch 1 mm and 100 divisions on the circular scale (c) an optical instrument that can measure length to within a wavelength of light?