Two radio antennas a and b radiate in phase. antenna b is a distance of 100 m to the right of antenna a. consider point q along the extension of the line connecting the antennas, a horizontal distance of 30.0 m to the right of antenna b. the frequency, and hence the wavelength, of the emitted waves can be varied. part a what is the longest wavelength for which there will be destructive interference at point q?

200 m

Explanation:

Path difference of waves from A and B = 100m

For destructive interference

Path diff = ( 2n+ 1 ) λ / 2

100 = ( 2n+ 1 ) λ / 2

λ = 200 / ( 2n+ 1 )

For maximum λ , denominator should be smallest  which is possible for

n =0

λ = 200 / 1

= 200 m

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: