Q: The side of a cube is measured by vernier calipers (10 divisions of the vernier scale coincide with 9 divisions of the main scale, where 1 division of main scale is 1 mm). The main scale reads 10 mm and first division of vernier scale coincides with the main scale. Mass of the cube is 2.736 g. Find the density of the cube in appropriate significant figures.

Sol. Least count of vernier calipers =(1 division of main scale )/(Number of division in vernier scale)

= 1/10 = 0.1 mm

The side of cube = 10 mm + 1 × 0.1 mm = 1.01 cm

Now,density = Mass/Volume

$\large = \frac{2.736}{(1.01)^3 cm^3}$

= 2.66 g cm^{-3}