What type of wave is emitted by a loud speaker?

Step 1: Analyze the question The question asks about the type of wave a loudspeaker produces. A loudspeaker produces sound, so we need to classify sound waves.

Step 2: Explain the concept

• A transverse wave has particles vibrating perpendicular to the direction the wave travels (e.g., light, water ripples, waves on a string).
• A longitudinal wave has particles vibrating parallel to the direction the wave travels. It forms compressions and rarefactions (e.g., sound waves).
• Gamma and radio waves are electromagnetic waves. They are transverse and are not produced by a loudspeaker's vibrating cone.

Step 3: Solution

1. A loudspeaker has a cone (diaphragm) that vibrates back and forth when an electrical signal passes through its coil.
2. As the cone moves forward, it pushes air particles together, creating a compression.
3. As it moves backward, it leaves a region of low pressure, creating a rarefaction.
4. The air particles vibrate back and forth along the same direction the sound travels.

This is the definition of a longitudinal wave.

Step 4: Eliminate the wrong options

• A. Transverse: sound in air is not transverse.
• C. Gamma: this is a high-energy electromagnetic wave from radioactive nuclei.
• D. Radio: this is an electromagnetic wave from a transmitter antenna, not from a loudspeaker's vibrating cone.

Answer: B. Longitudinal

Tip: Remember that sound = longitudinal = needs a medium. If a question mentions sound, think compressions and rarefactions. Any wave in the electromagnetic spectrum (radio, light, gamma, etc.) is transverse and can travel through a vacuum.