# Circular coil#

## Question Text#

How many turns must be wound on a flat, circular coil of radius 12.50$$\rm\ cm$$ in order to produce a magnetic field of magnitude $$2.60\times 10^{-4}$$ $$\rm\ T$$ at the centre of the coil when the current through it is 0.68$$\rm\ A$$?

$$N=$$