Is it true that if I want to have a good job I must have at least first class result as the average of all semesters?

Yes. As most good organizations asks for atleast 1st class.

yes if u want good job u must get first class through out..

no itz not necessary but if u want to work with reputated organisation then it require & plays a vital role b'coz a %age indicates how much a knowledge u have it differs u from others