Which of the following statement is correct but satellites ?

Options

A. A satellite cannot move in a stable orbit in a plane passing through the earth's centre.
B. Geostationary satellites are launched in the equatorial plane.
C. We can use just one geostationary satellite for global communication around the globe.
D. The speed of satellite increase with an increase in the radius of its orbit.

Explanation

To determine which statement about satellites is correct, let's analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: A satellite cannot move in a stable orbit in a plane passing through the Earth's center.**
- A satellite can indeed move in a stable orbit that passes through the Earth's center. The gravitational force provides the necessary centripetal force for the satellite to maintain its orbit. Therefore, this statement is **incorrect**.

2. **Statement 2: Geostationary satellites are launched in the equatorial plane.**
- Geostationary satellites are designed to orbit the Earth at the same rotational speed as the Earth itself, which means they remain fixed over one point on the equator. Hence, they must be launched in the equatorial plane. This statement is **correct**.

3. **Statement 3: We can use just one geostationary satellite for global communication around the globe.**
- A single geostationary satellite can only cover a specific area of the Earth’s surface. To provide global coverage, multiple satellites are required. Typically, at least three geostationary satellites are needed to cover the entire globe. Thus, this statement is **incorrect**.

4. **Statement 4: The speed of the satellite increases with an increase in the radius of its orbit.**
- According to Kepler's laws and the formula for orbital speed \( v = \sqrt{\frac{GM}{r}} \), where \( G \) is the gravitational constant, \( M \) is the mass of the Earth, and \( r \) is the radius of the orbit, the speed of a satellite actually decreases as the radius increases. Therefore, this statement is **incorrect**.

### Conclusion:
The only correct statement is **Statement 2: Geostationary satellites are launched in the equatorial plane.**

---