What is the least possible error encountered when taking measurement with a meter rule?

Answer Details

The least possible error encountered when taking measurements with a meter rule depends on the precision of the instrument being used. A typical meter rule has divisions of 1 mm, which means that the smallest distance that can be measured is 1 mm. However, with careful estimation, it may be possible to estimate the position of the edge of an object to within half a division, or 0.5 mm. Therefore, the least possible error encountered when taking measurements with a meter rule is 0.5 mm. Hence, the correct option is 0.5mm.