JEE MainPhysicsExperimental Physics
In a vernier caliper, N divisions of the vernier scale coincide with (N-1) divisions of the main scale. The length of one main scale division is a . When the two jaws are brought in contact, the zero of the vernier scale lies to the right of the zero of the main scale and its k^ th division coincides with a main scale mark. While measuring the length of a rod, the main scale reading is M divisions and the p^ th verni
Options
- Aa [ M + p-k N ]
- Ba [ M + p+k N ]
- Ca [ M + k-p N ]
- Da [ M + p N ]
Correct answer
A. a [ M + p-k N ]
Step-by-step solution
First, we determine the least count (L.C.) of the vernier caliper. Given 1 MSD = a and N VSD = (N-1) MSD . 1 VSD = N-1 N a L.C. = 1 MSD - 1 VSD = a - N-1 N a = a N When the jaws are in contact, the zero of the vernier scale is to the right of the main scale zero, which means the zero error is positive. Zero error = + k L.C. = + ka N During the measurement, the main scale reading is M divisions, which equals Ma . The vernier scale reading is p L.C. = pa N . Measured value = Ma + pa N The true length of the rod is ob