In a special 'retrograde' vernier caliper, 10 divisions of the vernier scale coincide exactly with 11 divisions of the main scale. If 1 main scale division is exactly 1 mm , the least count of this instrument in cm is:

Step-by-step solution

For a retrograde vernier, the vernier scale divisions are larger than the main scale divisions. Given that 10 VSD = 11 MSD , we can write: 1 VSD = 11 10 MSD = 1.1 MSD Since 1 MSD = 1 mm , we have 1 VSD = 1.1 mm . The least count (LC) is defined as the magnitude of the difference between one vernier scale division and one main scale division: LC = |1 MSD - 1 VSD | = |1 mm - 1.1 mm | = 0.1 mm Converting the least count to cm: LC = 0.1 mm = 0.01 cm . Answer: 0.01