Dear Sir,I'm appearing for the IIt for first time so can please give the detailed question paper format and also their marking system.It would be great if I get a sample paper...!!

Dear Aritra

Question Papers
There will be two question papers, each of three hours duration. Both the question papers would consist of three separate sections on Chemistry, Mathematics and Physics. Questions in these papers will be of objective type, which are to be answered on a specially designed machine-gradable sheet (ORS – Optical Response Sheet) using HB pencils only. Incorrect answers will be awarded negative marks

You can see previous years papers from thic this link

http://www.askiitians.com/iit-papers/IIT-JEE-Papers.aspx

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Askiitians Experts
Badiuddin