To solve this problem we will start from the given concept in which the number of turns is equivalent to the length of the thread per circumference of spool. That is:
[tex]N = \frac{l}{\phi}[/tex]
Where,
l = length of the thread
[tex]\phi[/tex]= circumference of spool
For \phi we have that,
[tex]\phi = 2\pi r \rightarrow 2\pi (0.01)[/tex]
For l we have that
l = 62.8m
Finally the number of Turns would be,
[tex]N = \frac{l}{\phi}[/tex]
[tex]N = \frac{62.8}{2\pi (0.01)}[/tex]
[tex]N = 1000turns[/tex]
Therefore the number of turns of thread on the spool are 1000turns.
