Question:
The vernier scale used for measurement has a positive zero error of
$0.2 \mathrm{~mm}$. If while taking a measurement it was noted that ' 0 ' on the vernier
scale lies between $8.5 \mathrm{~cm}$ and $8.6 \mathrm{~cm}$, vernier coincidence is 6 , then the
correct value of measurement is $\mathrm{cm} .$ (least count $=0.01 \mathrm{~cm}$ )
Correct Option: 2
Solution:
(2)
Positive zero error $=0.2 \mathrm{~mm}$
Main scale reading $=8.5 \mathrm{~cm}$ Vernier scale reading $=6 \times 0.01=0.06 \mathrm{~cm}$
Final reading $=8.5+0.06-0.02=8.54 \mathrm{~cm}$