106Ans 1. 
Ques 3) Which one of the following has a dipole moment significantly different from zero ??
Ques 4) Which one of the following has smallest heat of combustion ?
Ques 5)Among xylenes, which is thermodynamically stable ?
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3 Answers
29Ans 2.. A>B>C
the double bond will be broken and Carbon in the five mambered ring gets -ve charge and the carbon in the three memebered ring gets +ve charge so aromaticity is attained in both the rings..same funda for B ..but since tropylium carbocation is less stable than that cyclopropene carbocation so A>B..and in case of C the π bonds cannot be broken into charges as one of the rings will become antiaromatic then..so there will be no rotation in C...
Ans3...A...the dipole moment wont be cancelled out as the OH grps are in cis format...
Ans 5... B for the explanation see this link
http://www.targetiit.com/iit-jee-forum/posts/which-one-stable-15066.html
