grade 11 physics sound waves quiz

📚 Quick Study Guide

• 🔍 Sound Waves: Longitudinal waves that travel through a medium (solid, liquid, or gas).
• 📈 Speed of Sound: Depends on the medium's properties (temperature, density, elasticity). In air, it's approximately $343 \text{ m/s}$ at $20^\circ \text{C}$.
• 🌊 Wavelength ($\lambda$): The distance between two consecutive compressions or rarefactions.
• ⏱️ Frequency (f): The number of complete waves that pass a point per second, measured in Hertz (Hz).
• 📢 Amplitude: The maximum displacement of particles from their rest position; related to the loudness of the sound.
• ➗ Wave Equation: Relates speed (v), frequency (f), and wavelength ($\lambda$): $v = f\lambda$.
• 🔊 Intensity (I): Power per unit area; measured in $\text{W/m}^2$.
• 👂 Decibel Scale (dB): Measures sound intensity level: $\text{dB} = 10 \log_{10} (\frac{I}{I_0})$, where $I_0$ is the threshold of hearing ($10^{-12} \text{ W/m}^2$).
• ➕ Doppler Effect: Change in frequency due to relative motion between the source and the observer.

🧪 Practice Quiz

1. Question 1: What type of wave is a sound wave?
   1. Longitudinal
   2. Transverse
   3. Electromagnetic
2. Question 2: What is the approximate speed of sound in air at $20^\circ \text{C}$?
   1. $300 \text{ m/s}$
   2. $343 \text{ m/s}$
   3. $400 \text{ m/s}$
3. Question 3: Which property of a sound wave is related to its loudness?
   1. Frequency
   2. Wavelength
   3. Amplitude
4. Question 4: The distance between two consecutive compressions in a sound wave is called:
   1. Frequency
   2. Wavelength
   3. Amplitude
5. Question 5: What is the unit of frequency?
   1. Meter
   2. Hertz
   3. Decibel
6. Question 6: Which of the following factors does *not* affect the speed of sound in a medium?
   1. Temperature
   2. Density
   3. Color
7. Question 7: What happens to the observed frequency of a sound wave if the source is moving towards the observer?
   1. Increases
   2. Decreases
   3. Remains the same