Question

What is the least count of a commonly used metre scale?

Answer 1

1. The smallest value that can be measured by the measuring instrument is called its least count.
2. The least count can also be referred to as the error associated with the resolution of the instrument.
3. To calculate the least count we use the formula given below
4. Least count = $\frac{\mathrm{Magnitude}\mathrm{of}\mathrm{a}\mathrm{division}}{\mathrm{Number}\mathrm{of}\mathrm{division}\mathrm{to}\mathrm{reach}\mathrm{that}\mathrm{magnitude}}$
5. In the case of a meter scale let us consider the magnitude 1cm. The number of divisions that have taken to reach is 10.
6. So, least count can be calculated as per the formula as $\frac{1\mathrm{cm}}{10}$ = 0.1cm or 1mm

Hence, least count of meter scale is 0.1 cm or 1 mm.