#### An experiment is conducted to measure the diameter of a small spherical object using vernier calipers. The main scale reading is $M=2.5\ cm$, and the vernier scale reading is $15$. The least count of the vernier calipers is $0.01\ cm$. Calculate the diameter of the spherical object.Option: 1 $2.65\ cm$Option: 2 $2.55\ cm$Option: 3 $2.70\ cm$Option: 4 $2.65\ mm$

Given values:
• Main scale reading $(M)=2.5\ cm$
• Vernier scale reading $(V)=15$
• Least count of the vernier calipers $0.01\ cm$
The total reading on the vernier calipers can be calculated by adding the
Total reading $=M+V$
Step 1: Calculate the total reading on the vernier calipers:
Total reading $= 2.5\ cm + 15 \ mm = 2.65 \ cm$

The least count of the vernier calipers is $0.01\ cm$, which means that one
division on the vernier scale corresponds to $0.01\ cm$.

Step 2: Calculate the actual reading by adding the number of vernier divi-
sions that coincide with the main scale reading from the total reading:

Actual reading $= MSD + VSD \times LC$
Actual reading $= 2.5 + 15 \times 0.01\ cm$
Actual reading $= 2.65 \ cm$
So ,correct option is A