The circular head of a screw gauge is divided into 50 divisions and the screw moves 1 mm ahead in two revolutions of the circular head. Its pitch would be:

1. 0.05 cm
2. 0.001 cm
3. 0.5 cm
4. 0.01 cm

Identify the incorrect statement from the following :

(a) A screw gauge is used to measure very small dimensions like the thickness of a wire or sheet.

(b) Vernier callipers is used to measure larger dimensions like the diameter of a sphere, internal or external diameter lengths, etc.

(c) Vernier callipers works on the principle of a sliding scale to measure fractional parts of a main scale.

(d) Vernier callipers has a higher precision with a larger least count whereas screw gauge has a lower precision with a smaller least count.

How can you decrease the least count of a vernier callipers?

Define the term 'Vernier constant'.