Final answer:
The least count of vernier calipers is the smallest measurement that can be read or measured using the instrument. To determine the least count, you need to compare the divisions on the main scale with the divisions on the vernier scale and calculate the ratio. The least count represents the accuracy of the instrument.
Step-by-step explanation:
The least count of vernier calipers is the smallest measurement that can be read or measured using the instrument. It represents the smallest division on the main scale that can be accurately measured using the vernier scale.
To determine the least count of vernier calipers, you need to compare the divisions on the main scale with the divisions on the vernier scale. Count the number of divisions on the main scale that are equal to one division on the vernier scale. The ratio of these divisions can be used to calculate the least count.
For example, if there are 20 divisions on the main scale and 19 divisions on the vernier scale that are equal to 18 divisions on the main scale, then the least count is calculated as:
Least count = (1 main scale division) / (number of vernier scale divisions) = 1 / (20 - 19/18) = 0.05 main scale division.