NEET2026PhysicsChapterActual
In a vernier callipers, 1 cm on the main scale is divided into M equal parts. It is observed that P divisions of the vernier scale coincide exactly with (P-2) divisions of the main scale. The least count of the vernier callipers (in mm) is:
Options
- A2 PM
- B20M P
- C10 PM
- D20 PM
Correct answer
D. 20 PM
Step-by-step solution
Value of 1 Main Scale Division (MSD) = 1 M cm = 10 M mm Given that P Vernier Scale Divisions (VSD) coincide with (P-2) Main Scale Divisions (MSD): P VSD = (P-2) MSD 1 VSD = P-2 P MSD The Least Count (LC) of the vernier callipers is given by: LC = 1 MSD - 1 VSD LC = 1 MSD - P-2 P MSD LC = 2 P MSD Substituting the value of 1 MSD in mm: LC = 2 P 10 M mm = 20 PM mm Answer: 20 PM