The least count of a vernier caliper refers to the smallest measurement that can be read or measured using the instrument. It is determined by the number of divisions on the main scale and the number of divisions on the vernier scale.
In a standard vernier caliper, the main scale typically has divisions of 1 millimeter (mm) or 0.5 mm. The vernier scale, which slides along the main scale, consists of a number of divisions that are slightly smaller than those on the main scale. The most common type of vernier scale has 10 divisions that cover a distance equal to 9 divisions on the main scale.
To determine the least count of the vernier caliper, you can use the formula:
Least Count = Value of 1 division on the main scale / Number of divisions on the vernier scale
Let's consider an example where the main scale has divisions of 1 mm, and the vernier scale has 10 divisions covering a distance of 9 divisions on the main scale:
Least Count = 1 mm / 10 = 0.1 mm
Therefore, in this example, the least count of the vernier caliper would be 0.1 millimeters (or 0.01 centimeters). This means that the instrument can measure readings to the nearest 0.1 mm or 0.01 cm.