Standing wave intensity nodes and antinodes Steps:

• Identify the graph as showing periodic maxima and minima in intensity along the wave.
• Recall that in a stationary sound wave, intensity maxima occur at displacement antinodes (pressure nodes) and minima at displacement nodes (pressure antinodes).
• Measure distance between consecutive maxima to find λ/2, confirming standing wave pattern.
• Match graph features to choice A, which correctly describes node positions at intensity minima.

Why A is correct:

• Intensity is proportional to the square of pressure amplitude; at pressure antinodes (displacement nodes), intensity reaches zero, per wave superposition principle.

Why the others are wrong:

• B: Ignores that sound intensity minima are at nodes, not uniform.
• C: Misplaces antinodes; maxima are at displacement antinodes, not nodes.
• D: Contradicts standing wave formation; traveling waves have constant intensity envelope.

Final answer: A