You are currently doing your B.Tech in the first semester, you are thinking about changing to Bsc in Delhi. These are not an easy question for us to say go for option 1 or option 2.
1.Many students have a dilemma like this even after they start a particular course. We need to think rationally based on your strengths, aptitude, financial commitments and career prospects after each degree. Then it would be a good decision to choose to continue or change.
2.First list out your strength and aptitude. Is our core strength Physics and mathematics and do you have the aptitude to pursue it and succeed. Similarly, assess for computer science.
3.The check the fee structure. Currently, per semester fees at LPU for B.Tech is around 94,500/-. This is a 4-year course. It is recognized by UGC. For B.Sc Physics per semester ranges from 15,000-40,000 depending on the college. The comes to the hostel feeds and campus expenses which you can adjust to more or less the same in both.
4. Consider the career options of both. After B.Tech CSE, you can pursue M.TEch, try the GATE exam and aim at a professional career or an academic career. The options for employment is good both in private and public sector. The chance of overseas work placement is also good. You can see yourself as a Technical lead, software developer, Content writer, analyst, support specialist or even into research and DRDO jobs.
After B.Sc physics you can follow M.Sc and Ph.D. to become a faculty, a scientist in premier institutions like IIT, ISRO, IISc or even pursue cosmology career. Here it's more of research-oriented with placements in CSIR labs and opportunities for overseas fellowship and space-related jobs.
5. Please prepare a brief summary of the above and then meet a couple of your favourite teachers or well-wishers who has done similar courses and gather their inputs. These people will have a practical bird's eye view of how you would be suited for each of them.
6. After that, you can take a decision on continue B.Tech or switch over to B.Sc Both have good career prospectus in their own right, we need to assess which is more suited for you based on the above.