Complete destructive interference of echo reflections will affect the display in the following way:

Complete destructive interference of echo reflections will affect the display in the following way:

• A. Bright white pixel
• B. Black pixel
• C. Dark gray pixel
• D. Light gray pixel

Answer: (B)

Destructive interference happens when two echo reflections arrive at the detector with equal strength but opposite phase, canceling each other out. If they cancel completely, there’s no net echo detected, so the display shows zero brightness. Since brightness on the display correlates with echo amplitude, zero amplitude appears as a black pixel. Partial interference would yield dark gray or gray, while a bright white pixel would come from a strong constructive signal.

Destructive interference happens when two echo reflections arrive at the detector with equal strength but opposite phase, canceling each other out. If they cancel completely, there’s no net echo detected, so the display shows zero brightness. Since brightness on the display correlates with echo amplitude, zero amplitude appears as a black pixel. Partial interference would yield dark gray or gray, while a bright white pixel would come from a strong constructive signal.