Question

In a vernier callipers there are 10 divisions on vernier scale and 1cm on main scale is divided into 10 parts. While measuring a length the zero of vernier lies just ahead of 1.8 cm and 4th division of vernier coincides with main scale division. Find the length.

Answer 1

The least count is 0.01cm. 
Main scale reading = 1.8cm
Vernier scale division = 4(corresponds with main scale division)
Vernier scale reading = Vernier scale division×Least count
                                   = 4×0.01
                                   = 0.04cm
total reading = main scale reading+vernier scale reading
                     = 1.8+0.04
                     = 1.84cm

Answer 2

Answer: 1.84 cm

Explanation: