Doppler Effect Quiz with Answers: Test Your Understanding

📚 Quick Study Guide

• 🚗 Definition: The Doppler Effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source.
• 🎵 Sound Waves: When a sound source moves towards you, the pitch sounds higher; when it moves away, the pitch sounds lower.
• 💡 Light Waves: Similar effect with light; approaching light shifts towards blue (higher frequency), receding light shifts towards red (lower frequency).
• 🔢 Formula (Approaching): $f' = f(\frac{v + v_o}{v - v_s})$, where $f'$ is the observed frequency, $f$ is the source frequency, $v$ is the speed of the wave, $v_o$ is the observer's speed, and $v_s$ is the source's speed.
• 📡 Formula (Receding): $f' = f(\frac{v - v_o}{v + v_s})$.
• 🛰️ Applications: Used in radar, astronomy, and medical imaging.

🧪 Practice Quiz

1. A car is moving towards you while honking its horn. What happens to the sound you hear?

   1. The pitch of the horn remains the same.
   2. The pitch of the horn sounds lower.
   3. The pitch of the horn sounds higher.
   4. The loudness of the horn decreases.

2. A train is moving away from you. How does the frequency of the train's whistle change according to the Doppler effect?

   1. The frequency increases.
   2. The frequency decreases.
   3. The frequency remains constant.
   4. The frequency becomes zero.

3. What type of wave is affected by the Doppler effect?

   1. Only sound waves.
   2. Only light waves.
   3. Both sound and light waves.
   4. Neither sound nor light waves.

4. In the Doppler effect formula, what does $v_s$ represent?

   1. The speed of the observer.
   2. The speed of the source.
   3. The speed of sound.
   4. The speed of light.

5. Which of the following is an application of the Doppler effect in astronomy?

   1. Measuring the distance to stars.
   2. Measuring the temperature of stars.
   3. Measuring the speed of stars moving towards or away from us.
   4. Measuring the mass of stars.

6. If a star is moving towards Earth, what happens to the light emitted by the star?

   1. It is redshifted.
   2. It is blueshifted.
   3. It remains the same color.
   4. It turns green.

7. What happens to the observed frequency if both the source and the observer are stationary?

   1. The observed frequency is higher than the source frequency.
   2. The observed frequency is lower than the source frequency.
   3. The observed frequency is the same as the source frequency.
   4. The observed frequency is zero.