A solenoid 74.5 cm long has 350 turns and

a radius of 2.26 cm.
If it carries a current of 1.69 A, find the
magnetic field along the axis at its center.
Answer in units of T

2 answers

Magnetic field = permeability x turn density x current

For a solenoid of length L =0.745m with N =350 turns,
the turn density is n=N/L turns/m.
If the current in the solenoid is I =1.69 amperes
and the relative permeability of the core is k =1( air)
then the magnetic field at the center of the solenoid is

1*(350/.745)*1.69 T
It says its wrong