A vernier callipers has $20$ divisions on the vernier scale, which coincides with $19^{\text {th }}$ division on the main scale. The least count of the instrument is $0.1 \mathrm{~mm}$. One main scale division is equal to $. . .  . . ..$ $\mathrm{mm}$

A screw gauge has least count of $0.01\, mm$ and there are $50$ divisions in its circular scale. The pitch of the screw gauge is $……..mm$

In an experiment with Vernier callipers of least count $0.1\,mm$, when two jaws are joined together the zero of Vernier scale lies right to the zero of the main scale and $6^{\text {th }}$ division of Vernier scale coincides with the main scale division. While measuring the diameter of a spherical bob, the zero of vernier scale lies in between $3.2\,cm$ and $3.3\,cm$ marks, and $4^{\text {th }}$ division of vernier scale coincides with the main scale division. The diameter of bob is measured as $…….\,cm$

A travelling microscope has $20$ divisions per $cm$ on the main scale while its Vernier scale has total $50$ divisions and $25$ Vernier scale divisions are equal to $24$ main scale divisions, what is the least count of the travelling microscope $……….\,cm$

The vernier constant of Vernier callipers is $0.1 \,mm$ and it has zero error of $(-0.05) \,cm$. While measuring diameter of a sphere, the main scale reading is $1.7 \,cm$ and coinciding vernier division is $5$. The corrected diameter will be ……….. $\times 10^{-2} \,cm$