The picture shows a basic diagram of an electric motor. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire X sits attached to a metal rod, which runs between the 2 pieces of magnet. 2 semicircular pieces Z of metal surround the rod at its opposite end from the pieces of magnet. Wires connect to each semicircular piece at terminals Y to one pole of a battery. Blue arrows superimposed on the end of the coil away from the magnets point toward S and away from N. Which labels best complete the diagram? X: Brush Y: Armature Z: Commutator X: Commutator Y: Brush Z: Armature X: Armature Y: Commutator Z: Brush X: Armature Y: Brush Z: Commutator

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: