some Q's wil post more later for now take these

well guys it's only testing your analytical skills partly and some chemistry skills . read the first passage carefully.and answer

it's easy . yet gave.
and second one organic is nice. try it .

passage for 1st

@ rom temp , Fe exists in bcc form known as α-iron. above 910⁰C , it transforms to fcc form . called as γ-iron . Above 1390⁰C , it again exists in bcc form known as δ-iron . iron melts at 1535⁰C .

pure iron is ferromagnetic as a result of extensive magnetic interactions b/w unpaired e-s of adjacent atoms wihch cause e- spins to be alignned in the same direction . It has a curie temp of 768⁰C . above this temp , thermal energy overcomes interaction b./w e-s localised on individual atoms, thier mutual alignmetn is broken

Q1) if a sample of pure iron is ferromagnetic . then unit cell of that material is
A) i B) ii
C) iii D) either i or ii

Q2) if pure iron at some temp is found to have a unit cell shown by i , then material at that temp is

A) ferromagnetic
B) paramagnetic
C) eihther ferro or para
D) doesn't correspond to α,γ or δ-iron

Q3)
unit cell of paramagnetic iron is given by

A) i
B) iii
C) i or ii
D) ii or iii