Physics Spl

You can do B.Sc. in physics and continue with PhD or teaching level.

Concentrate more on basic concepts and try to solve as many different problems as possible.

Firstly, refer NCERT for PCM and try all the problems to get you basic concepts cleared and then go for reference books like H.C.Verma for Phy., M.L.Khanna for Maths and O.P.Tandon for chemistry. I would suggest you to join a coaching as it will assist you in preparing in a proper curriculum with weekly tests to evaluate your preparation.

You can go for M.Sc with physics. B.Sc physics has good scope in teaching in school, tuition and college.it is important in research field.

IIT preparations will help you to crack NDA provided you are able to put additional effort on general awareness.

Every ray of light bends, but for all practical purposes, the bending is negligible to have any real effect on day to day applications. Only a huge mass like the sun has enough gravitational attraction to significantly alter the path of a ray of light. So what you call normal is actually straight for practical applications.
Bending of light is used by scientists to measure the mass of huge objects. The amount of bending is directly proportional to the mass of the object causing it.