Doppler effect is applicable to

Options

A. sound waves
B. light waves
C. radio waves
D. all the above

Answer

To solve the question regarding the applicability of the Doppler effect, we can follow these steps:

### Step 1: Understand the Doppler Effect
The Doppler effect refers to the change in frequency (or wavelength) of a wave in relation to an observer who is moving relative to the wave source. This effect can be observed in various types of waves.

**Hint:** Remember that the Doppler effect is about the relative motion between the source of the wave and the observer.

### Step 2: Identify the Types of Waves
Waves can be categorized into two main types:
- **Mechanical Waves:** These require a medium to travel through (e.g., sound waves).
- **Electromagnetic Waves:** These do not require a medium and can travel through a vacuum (e.g., light waves, radio waves).

**Hint:** Think about the characteristics of mechanical and electromagnetic waves when considering their applicability to the Doppler effect.

### Step 3: Analyze the Options
The question provides the following options:
1. Sound wave (mechanical wave)
2. Light wave (electromagnetic wave)
3. Radio wave (electromagnetic wave)
4. All of the above

Since both mechanical and electromagnetic waves can exhibit the Doppler effect, we need to evaluate each option.

**Hint:** Consider if each type of wave can experience a change in frequency due to the motion of the source or observer.

### Step 4: Conclusion
Since the Doppler effect is applicable to sound waves (mechanical), light waves (electromagnetic), and radio waves (electromagnetic), the correct answer is:
- **All of the above.**

**Final Answer:** D) All of the above