Wavelength And Frequency

Step 1: Destructive interference occurs when two waves of the same frequency and amplitude are exactly out of phase. Here, the phase difference between waves (i) and (ii) is , which will result in destructive interference.
Step 2: The waves with phase differences of or will result in stationary waves. The waves (i) and (ii) will combine to form stationary waves due to their phase relationship. Similarly, waves (iii) and (iv) will also form stationary waves.
Step 3: Therefore, the correct pairs are (i), (ii), (iii), and (iv) for destructive interference and stationary waves.