# The vernier scale used for measurement has a positive zero error of

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 $=0.01 \mathrm{~cm}$ )

1. (1) $8.36 \mathrm{~cm}$

2. (2) $8.54 \mathrm{~cm}$

3. (3) $8.58 \mathrm{~cm}$

4. (4) $8.56 \mathrm{~cm}$

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 $=8.5+0.06-0.02=8.54 \mathrm{~cm}$