The magnetic field at the center of a solenoid L = 75 cm in
length is B = 0.43 T when a current of I = 7.5 A flows through the
solenoid wire.
a. Solve the formula for the magnetic field near the center
of a long, tightly wound solenoid for the number of
turns, N, in the solenoid. The expression should be
in terms of the given variables.
b. Calculate the value of the number of
turns, N.