Question

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?

Answer 1

200 m

Step-by-step 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