Question

Match the following measuring instruments with their typical values of least counts.

• A. $0.001cm$
• B. $0.1cm$
• C. $0.01cm$

Answer 1

• Metre scale has 100 cm with 10 subdivisions in each centimetre , i.e least count = $\frac{1}{10}cm=0.1cm$
• Vernier callipers has generally 10 vernier scale divisions(n) and the value of one main scale division(x) is 1 mm, i.e. least count = $\frac{x}{n}=\frac{1}{10}mm$ $=0.1mm=0.01cm$
• Screw gauge has generally 100 circular scale divisions(n) and the value of one main scale division(x) is 1 mm, i.e. least count = $\frac{x}{n}=\frac{1}{100}mm$ $=0.01mm=0.001cm$.