The ends of a magnet where the forces are the strongest are called magnetic

Poles

Explanation:

Each magnet has two poles - North pole and south pole at its end. The magnetic field strength is maximum at the poles. The magnetic field lines exit the magnet from North pole and enter at south pole.

These field lines form closed loops around the magnet. The magnetic field lines are the regions where the magnetic force is exerted by the magnet. This force is strongest at the poles.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

increases it