Question

What is least count and how we can find it

Answer 1

The least count of an instrument is the smallest change in the value that can be measured with the measuring instrument.

Least count = 1 main scale division - 1 vernier scale division

Now, we know

10 divisions in main scale = 1cm

1 division in main scale( 1 MSD) = 1/10 = 0.1 cm

10 division in vernier scale = 9 division on main scale

1 division in vernier scale(1 VSD) = 9/10 division on main scale(MSD)

Least count = 1 MSD - 1 VSD = (1–9/10) MSD

Least count = 1/10 MSD = 0.1 × 0.1 = 0.01 cm

Least count = 0.01 cm (ans)

hope you understand...