Intensity of electric field obtained at receiver antenna for a space wave propagation is

Options

A. directly proportional to the perpendicular-distance from transmitter to antenna
B. inversely proportional to the perpendicular-distance from transmitter to antenna
C. directly proportional to the square perpendicular distance from transmitter to antenna
D. inversely proportional to the square perpendicular distance from transmitter to antenna

Explanation

To determine the intensity of the electric field obtained at the receiver antenna for space wave propagation, we can analyze the relationship between the electric field intensity and the distance from the transmitter.

### Step-by-Step Solution:

1. **Understanding the Concept**:
- The electric field intensity (E) at the receiver antenna is influenced by the distance (d) from the transmitter. In free space, as the distance increases, the intensity of the electric field decreases.

2. **Identify the Formula**:
- The electric field intensity can be expressed as inversely proportional to the square of the distance from the transmitter. Mathematically, this can be represented as:
\[ E \propto \frac{1}{d^2} \]
- Here, \(d\) is the perpendicular distance from the transmitter to the receiver antenna.

3. **Analyzing the Options**:
- Given the options:
1. Directly proportional to the perpendicular distance
2. Inversely proportional to the perpendicular distance
3. Directly proportional to the square of the perpendicular distance
4. Inversely proportional to the square of the perpendicular distance

4. **Choosing the Correct Option**:
- Since we established that the electric field intensity is inversely proportional to the square of the distance, the correct option is:
\[ \text{Inversely proportional to the square of the perpendicular distance from the transmitter to the antenna} \]

5. **Conclusion**:
- Therefore, the intensity of the electric field obtained at the receiver antenna for space wave propagation is inversely proportional to the square of the distance from the transmitter.

### Final Answer:
The intensity of the electric field obtained at the receiver antenna for space wave propagation is inversely proportional to the square of the perpendicular distance from the transmitter to the antenna.

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