Two ordinary satellites are revolving round the earth in same elliptical orbit, then which of the following quantities is conserved :-

Options

A. Velocity
B. Angular velocity
C. Angular momentum
D. None of above

Answer

To determine which quantities are conserved for two ordinary satellites revolving around the Earth in the same elliptical orbit, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Motion of Satellites**:
- Both satellites are in elliptical orbits around the Earth. In such orbits, the motion is governed by gravitational forces.

2. **Analyzing Velocity**:
- The velocity of a satellite changes as it moves along its elliptical path. At different points in the orbit, the speed (magnitude of velocity) varies due to the changing distance from the Earth.
- **Conclusion**: Velocity is NOT conserved.

3. **Analyzing Angular Velocity**:
- Angular velocity, which is the rate of change of the angle with respect to time, also varies as the satellite moves along the elliptical path. The angular velocity is not constant throughout the orbit.
- **Conclusion**: Angular velocity is NOT conserved.

4. **Applying Kepler's Second Law**:
- According to Kepler's Second Law (the law of areas), a line segment joining a planet (or satellite) and the Sun (or Earth) sweeps out equal areas during equal intervals of time. This implies that the angular momentum of the satellite is conserved when it is in orbit.
- **Conclusion**: Angular momentum is CONSERVED.

5. **Final Conclusion**:
- Among the quantities considered (velocity, angular velocity, and angular momentum), only angular momentum remains conserved for the two satellites in the same elliptical orbit.

### Answer:
The conserved quantity is **Angular Momentum**.