You are given a thread and a metre scale. How will you estimate the diameter of the thread ?

Explanation

Given string is wound on pencil in such a way that tums are very close to each other tightly packed. We get no. of turns by measuring with scale let length of this loop is L Let number of turns in loop are n.
`:.` Length of each turn = thickness of each
`turn=(l)/(n)`
This thickness will be equal to diameter (thickness) of string.