Answer: Destructive.
- A Constructive
- B Destructive
- C Neither
- D Both constructively and destructively
Correct answer: B. Destructive
Explanation: Phase difference of pi (180 degrees) = path difference of lambda/2. Destructive interference (waves cancel).
A standing wave forms from two identical waves travelling in opposite directions and interfering; nodes (always zero displacement) and antinodes (maximum displacement) stay fixed in place, unlike a travelling wave where the whole pattern moves.
Concept context
Wave types, superposition, standing waves, Doppler effect, and sound intensity.