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The diameter of a cylinder is measured using a Vernier callipers with no zero error. It is found that the zero of the Vernier scale lies between 5.10 cm and 5.15 cm of the main scale. The Vernier scale has 50 divisions equivalent to 2.45 cm. The 24th division of the Vernier scale exactly coincides with one of the main scale divisions. The diameter of the cylinder is

1. 5.11 cm
2. 5.124 cm
3. 5.136 cm
4. 5.148 cm

Correct answer: 5.124 cm

Solution

The main scale reading is between 5.10 cm and 5.15 cm, and the Vernier scale reading is calculated as (24 × 2.45 cm) / 50 = 0.124 cm. Adding this to the main scale reading gives 5.124 cm as the diameter.

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