In a vernier callipers, $(N+1)$ divisions of vernier scale coincide with $N$ divisions of main scale. If $1 \mathrm{MSD}$ represents $0.1 \mathrm{~mm}$, the vernier constant (in $\mathrm{cm}$ ) is:

The vernier scale of a travelling microscope has $50$ divisions which coincide with $49$ main scale divisions. If each main scale division is $0.5\, mm$, calculate the minimum inaccuracy in the measurement of distance.

A student measures the thickness of a human hair by looking at it through a microscope of magnification $100$. He makes $20$ observations and finds that the average width of the hair in the field of view of the microscope is $3.5 \;mm$. What is the estimate on the thickness(in $mm$) of hair ?

In a vernier callipers, $10$ divisions of vernier scale coincides with $9$ divisions of main scale, the least count of which is $0.1\,cm$. If in the measurement of inner diameter of cylinder zero of vernier scale lies between $1.3\,cm$ and $1.4\, cm$ of main scale and $2^{nd}$ division of vernier scale coincides with main scale division then diameter will be ………. $cm$

The diameter of a sphere is measured using a vernier caliper whose $9$ divisions of main scale are equal to $10$ divisions of vernier scale. The shortest division on the main scale is equal to $1 \mathrm{~mm}$. The main scale reading is $2 \mathrm{~cm}$ and second division of vernier scale coincides with a division on main scale. If mass of the sphere is $8.635 \mathrm{~g}$, thedensity of the sphere $1 \mathrm{~s}$ :