in an experiment the angles are required to be using an instrument, `29` divisions of the main scale exactly coincide with the `30` divisions of the vernier scale. If the sallest division of the main scale is half- a degree `(= 0.5^(@)`, then the least count of the instrument is :

Explanation

Least count `= ("Value of main scale division")/("No.of divisons of vernier scale")`
`= (1)/(30) MSD = (1)/(30)xx(1^(0))/(2) = (1^(0))/(60) = 3` min