Question 1:
easy
The vernier scale of a callipers is divided into 20 divisions which coincide with 18 main scale divisions. Each main scale division is 0.2 mm. The least count of the instrument is
Least count (LC) is given by \(text{LC} = 1text{ MSD} - 1text{ VSD}\). Since 20 VSD = 18 MSD, we have \(1text{ VSD} = 0.9text{ MSD}\). Thus, \(text{LC} = 0.1text{ MSD} = 0.1 times 0.2text{ mm} = 0.02text{ mm}\).