Question

For the first transition series, the orbital angular momentum is of no significance. Why? Explain in detail.

Answer 1

In an orbit under the influence of gravitational or electrostatic attraction, angular momentum is conserved. This is because the gravitational force and the electrostatic force are both central forces. Central forces depend only on radius, not direction, and as such never exert torques. In the absence of a net external torque, objects maintain constant total angular momentum.

Kepler's second law (planets sweep out equal areas in equal times) is a result of the conservation of angular momentum by planets; they move faster when closer to the sun and slower when further away.