A device known as an optical resonator is used in lasers. An optical resonator consists of an arrangement of mirrors that reflect electromagnetic radiation back and forth within an empty cavity. The electromagnetic radiation within the cavity reflects off of the mirrors multiple times. The mirrors are precisely placed so that only particular frequencies can survive within the cavity via constructive interference. All other frequencies are suppressed via destructive interference. The end result is a beam of light of a certain frequency. An optical resonator of the type described above depends on the tendency of light to
A. behave as a wave.
B. excite atoms to certain energy levels.
C. excite electrons to certain energy levels.
D. behave as a particle.

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: