I am applicant for IIT-MAINS 2015 with application no. 50263806. My result for this session is declared but I am not satisfied with it. I am in need for just one mark. I have query in a question which is in the question paper of IIT JEE MAINS 2015. I just want to know the correct explanation for this question. There was no specification about the criterion on which we have to answer,it can be interaction energy and interaction force. In my opinion it has two correct answers. (Code D : Question 75). (Code C : Question 74). (Code A : Question 34). (Code B : Question 20).