Which of the following is NOT a transverse wave?

• A. Wave on a stretched string
• B. Wave on the surface of water (approximately transverse for small amplitudes)
• C. Sound wave in air
• D. Electromagnetic wave (light)

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the difference between transverse and longitudinal waves. In transverse waves, the particle displacement is perpendicular to the direction of wave propagation. In longitudinal waves, the particle displacement is parallel to the direction of wave propagation.
2. Step 2: Analyze the wave on a stretched string. The particles of the string move up and down (perpendicular) while the wave travels along the string, so this is a transverse wave.
3. Step 3: Consider the wave on the surface of water. For small amplitudes, the water particles move mostly perpendicular to the direction of wave travel, making it approximately a transverse wave.
4. Step 4: Examine the sound wave in air. Sound waves are pressure waves where air particles oscillate back and forth in the same direction as the wave travels, which means sound waves are longitudinal waves.
5. Step 5: Look at electromagnetic waves (like light). These waves consist of oscillating electric and magnetic fields perpendicular to the direction of propagation, so they are transverse waves.