hi i also have come across these questions.. and i have not been able to find suitable answers to them..
1) why do u think mba??
ans) mba gives u all managerial levels which i haven't got in my BE course..
it seems that answer is not sufficient..
doesn't mba give this

.... more i think abt more i get confused..
2) u don't have any knowledge about the industry so u don't know anything about electronics.. ( i m fresher and have completed BE Electronics)
what could be the answer to this?? i couldn't answer it.
3) what has the institute gained from u??
i couldn't answer this too.. this was asked in mock interview and they also didn't have proper answer to this..
if any1 has answers then plz poost them