Mechanical engineering almost works using physics.
What you learn is thermodynamics, fluid mechanics, solid mechanics, design of machine, manufacturing, etc.
Physics also applied in electrical, electronics and civil engineering.
But the vast physics lies only in mechanical branch.

Honestly, solving problems in physics and pursuing a career in Physics are two different things.
You might consider Electrical Engineering or Mechanical Engineering depending on your choice of topics you like in Physics.
A B.Sc. in Physics will allow you to do more of research than exact problem solving. There are many streams though, like Granular Physics etc etc.

Hello ,

With a basic degree - a B.Sc, B.E or B. Tech, which can be pursued after 12th, you can choose to explore various fields and find the one that best suits your subject of BSC physics.

For more details go for this link
http://www.mapmytalent.in/blog/career-options-after-12th-in-physics

I am telling you about these 2 courses which are very demanding right now ::

1) Biophysics
2) Biochemistry