all

both hr type and subject based

Questions r asked on the topic(post) for which u r 
appearing an interview. Also on what u have done earlier.

If u are a fresher, u need to be thorough with ur acedemics 
and also about the project (very imp) you did in your final 
year. They may stress more upon the fundamentals of the 
subject.

questions r asked depends on ur experience and ur exposure 
if u r fresher most of the quesstions aksed by seeing ue cv 
and about ur project and ur intereasted subjects.if u r 
experienced questions asked from ur earlier work.but mostly 
basics of all subjects.