NEETPhysicsExperimental Physics
The main scale of a vernier calipers has divisions of length a . It is found that n divisions of the vernier scale coincide with (n-2) divisions of the main scale. The least count of the vernier calipers is :
Options
- Aa n
- B2a n
- C(n-2)a n
- Da n-2
Correct answer
B. 2a n
Step-by-step solution
Given n VSD = (n-2) MSD . 1 VSD = n-2 n MSD . The least count is given by 1 MSD - 1 VSD . Least count = 1 MSD - n-2 n MSD Least count = (1 - n-2 n ) MSD = ( n - n + 2 n ) MSD = 2 n MSD . Since 1 MSD = a , the least count is 2a n . Answer: 2a n