A student investigates the behaviour of a progressive microwave signal of wavelength λ\lambdaλ.
As shown in the diagram, a transmitter directs a stable signal towards a receiver. The receiver is mounted on a graduated track and can be slid along the direction of wave propagation.
When the receiver is moved a distance Δx \Delta x\,Δx away from the transmitter, the phase of the detected signal changes by 3π2 rad\displaystyle \frac{3\pi}{2}\text{ rad}23π rad relative to its initial phase.
What is the ratio Δxλ\displaystyle \frac{\Delta x}{\lambda}λΔx?
38\frac{3}{8}83
34\frac{3}{4}43
43\frac{4}{3}34
32\frac{3}{2}23