As per the notification issued by UPSC on March 5, 2013 there are certain changes in the scheme of Main Examination.
Visit following links to know more about the new scheme
Civil Services Examination 2013
Useful Read:
Preliminary Examination PAPER I: (General Studies) Syllabus Preliminary Examination/CSAT Paper II: (Aptitude Test) SYLLABUS
Preliminary Examination Paper I - Recent Question Papers Prelims/CSAT - Paper II - Recent Question Papers
Prelims 2013: time for action