7. In a vernier callipers, there are 10 divisions on the
vernier scale and 1 cm on the main scale is divided
in 10 parts

7. In a vernier callipers, there are 10 divisions on the
vernier scale and 1 cm on the main scale is divided
in 10 parts. While measuring a length, the zero of
the vernier lies just ahead of 1.8 cm mark and 4th
division of vernier coincides with a main scale
division.
(a) Find the length.
(b) If zero error of vernier callipers is – 0.02 cm,
what is the correct length ?
Ans. (a) 1:84 cm, (b) 1.86
with process please​