Question

A vernier calliper has 20 divisions on the vernier scale, which coincide with 19 on the main scale. The least count of the instrument is 0.1 mm. The main scale divisions are of ______.

Options

• 0.5 mm

• 1 mm

• 2 mm

• 1/4 mm

Answer 1

A vernier calliper has 20 divisions on the vernier scale, which coincide with 19 on the main scale. The least count of the instrument is 0.1 mm. The main scale divisions are of 2 mm.

Explanation:

20V = 19S

V = `19/20` S

S - V = `"S" - 19/20` S

⇒ vernier = `"S"/20`

0.1 mm = `"S"/20`

∴ 1s = 20 × 0.1 mm

= 2 mm