Answer: 0.02 s.
- A 0.001 s
- B 0.02 s
- C 0.1 s
- D 50 s
Correct answer: B. 0.02 s
Explanation: T = 1/f = 1/50 = 0.02 s.
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.