My question is that sat and TOEFL is necessary for study in USA but any other exams will be taken by university for b tech degree.

This tense is important for students. It helps improve grammar skills. Students use it in speaking and writing tests.

Correct use makes sentences better. It also helps explain ongoing actions clearly. 

Online coaching for TOEFL is more flexible and affordable for most students. Many candidates are working, so online TOEFL classes are a better option.

The fees for TOEFL coaching in India range between INR 10,000 and INR 50,000. Shiksha offers free TOEFL classes in online mode.

Jamboree, T.I.M.E, Shiksha Free Classes, Magoosh, and Manhattan Review are among popular TOEFL coaching classes in India.

No, a TOEFL-iBT score of 50 is likely too low for getting a seat at Carolina Uni. As per the university's admission policy, international students usually need an overall score of atleast 60, a paper-based score of 500, or a computer based score of 170 to study here.