Offtopic
Dear Meritnation,
Please take into consideration one thing.
For - NCERT Physics Class 11 Study Material - Chapter 8 (Gravitation) - Lesson 1 - Videos By Teacher - 1st Video (Kepler 1st Law)
Recommendation - Please remake that video and this time try not to put the pen near the midpoint of the thread while making an ellipse. Students can understand ellipse better if you keep one the distance from either focii a lil different because I'm sure most of the student couldn't differentiate between that 'circular ellipse' and the circle!
We have added your suggestions into our content-addition list and will try to come up with it in near future.