What is the radiowaves signal called if it propagates from one place to another along the surface of the earth?

Options

A. Sky wave
B. Ground wave
C. Carrier wave
D. Modulated wave

Answer

To solve the question, "What is the radio wave signal called if it propagates from one place to another along the surface of the earth?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Types of Radio Wave Propagation**:
- There are different modes of radio wave propagation, including ground waves, sky waves, carrier waves, and modulated waves. Each has distinct characteristics and methods of transmission.

2. **Defining Each Type**:
- **Sky Wave**: This type of wave is reflected off the ionosphere and can travel long distances by bouncing between the ionosphere and the earth.
- **Ground Wave**: This type of wave travels along the surface of the earth. It is used for communication over short to medium distances.
- **Carrier Wave**: This is a high-frequency wave that carries the information signal (modulating wave) but does not propagate itself.
- **Modulated Wave**: This is the combination of the carrier wave and the information signal, which is the result of modulation.

3. **Identifying the Correct Answer**:
- The question specifically asks for the type of radio wave that propagates along the surface of the earth. Based on the definitions provided, the correct answer is the **Ground Wave**.

4. **Conclusion**:
- Therefore, the radio wave signal that propagates from one place to another along the surface of the earth is called a **Ground Wave**.

### Final Answer:
The radio wave signal that propagates along the surface of the earth is called a **Ground Wave**.

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