Assertion : Plane of a satellite always passes through the centre of earth
Reason : Gravitational force on satellite is always towards centre of earth.

Options

A. If both Assertin and Reason are correct and Reason is the correct explanation of Assertion
B. If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
C. If Assertion is true but Reason is false
D. If Assertion is false but Reason is true

Answer

To solve the assertion-reason question, we need to analyze the two statements provided:

**Assertion:** The plane of a satellite always passes through the center of the Earth.
**Reason:** The gravitational force on the satellite is always directed towards the center of the Earth.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- The assertion states that the plane of a satellite's orbit passes through the center of the Earth. This is a characteristic of orbital motion. When a satellite orbits the Earth, it moves in a circular or elliptical path. The plane of this orbit can be visualized as a flat surface that extends infinitely in all directions from the orbiting satellite.

2. **Visualizing the Orbit:**
- Imagine a satellite in orbit around the Earth. If you were to draw a circle (for a circular orbit) or an ellipse (for an elliptical orbit) around the Earth, the center of this circle or ellipse would be the center of the Earth. The plane of the orbit is defined by this circular or elliptical path.

3. **Analyzing the Reason:**
- The reason states that the gravitational force acting on the satellite is always directed towards the center of the Earth. This is indeed true; gravitational force is a central force, meaning it acts along the line connecting the center of the Earth and the satellite.

4. **Connecting Assertion and Reason:**
- Since the gravitational force acts towards the center of the Earth, it ensures that the satellite remains in a stable orbit. The plane of the orbit, which is defined by the path of the satellite, must necessarily pass through the center of the Earth because the gravitational force is always directed towards that center.

5. **Conclusion:**
- Both the assertion and the reason are true. The assertion correctly describes the geometric relationship of the satellite's orbit with respect to the Earth, and the reason accurately explains the nature of the gravitational force acting on the satellite.

### Final Answer:
- **Assertion is True.**
- **Reason is True.**
- **Both are related.**