Hello,

the sun together with the group of celestial bodies that are held by its attraction and revolve around it also : a similar system centered on another star.

The term Solar System refers to the "family" of the Sun. The Sun is a star around which eight planets, among other celestial objects, revolve in orbits.

Thank you.

@ AANCHAL WADHWANI you can study the books of your state. You can go through  sst books of class 9th and 10th of your state boards and do some important topics from NCERT and about the topics related to ancient history you should prefer the state boards books of class 8th or you can just download the pdf for the topics of ancient india. At the end preference to the state books is must for stage 1 . HOPE IT WILL HELP FOR YOU  :)

Hello!!

no external torque→angular momentum conservedno external force→linear momentum conservedno external torque→angular momentum conservedno external force→linear momentum conserved

There is no external torque about the sun since the force of the sun and position vector are always at an angle 180180 since τ¯=r¯×F¯τ¯=r¯×F¯ , so angular momentum is conserved.

But since the path in not circular but elliptical , the position vector is not perpendicular to direction of motion hence some work is done, which changes the momentum indirectly by changing magnitude of velocity directly.

Thanks

You need to practice a lot for such types of numericals.. You can refer to some books like Marvel or USS and thus increase your knowledge and skill-set as well.

Best wishes. Thankyou.