A ground receiver in line-of-sight communication cannot receive direct waves due to

Options

A. its low frequency
B. curvature of earth
C. its high intensity
D. smaller antenna

Explanation

To solve the question "A ground receiver in line-of-sight communication cannot receive direct waves due to," we need to analyze the concept of line-of-sight communication and the factors that affect it.

### Step-by-Step Solution:

1. **Understanding Line-of-Sight Communication**:
- Line-of-sight (LOS) communication refers to a direct transmission path between a transmitter and a receiver. This means that the signals travel straight from the transmitter to the receiver without any obstruction.

2. **Identify the Factors Affecting LOS**:
- In an ideal scenario, if both the transmitter and receiver are at the same height and there are no obstacles (like buildings or trees), the communication can occur effectively.
- However, in real-world scenarios, especially on the surface of the Earth, the curvature of the Earth can affect this direct path.

3. **Curvature of the Earth**:
- The Earth is not flat; it has a curvature. When a signal is transmitted from a transmitter to a receiver on the ground, the signal must travel in a straight line.
- Due to the curvature of the Earth, the straight line path may not connect the transmitter and receiver if they are at a significant distance apart.

4. **Conclusion**:
- Therefore, a ground receiver in line-of-sight communication cannot receive direct waves because the curvature of the Earth obstructs the direct path of the signal. The signal may need to reflect off the ionosphere or use other forms of propagation to reach the receiver.

### Final Answer:
A ground receiver in line-of-sight communication cannot receive direct waves due to the curvature of the Earth.

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