In which pair most efficient packing is present. (a) HCP and BCC (b) HCP and CCP (c) BCC and CCP (d) BCC and simple
Option (b) is correct. Most efficient packing is seen in which the percentage of void or the percentage of the empty space is lowest. We can also say that most efficient packing is seen in which the packing fraction is highest. Packing fraction of simple cubic cell \(= 52\;\%\ \) approx FCC \(= 74\;\%\) approx BCC \(= 68\;\%\) approx HCP\(= 74\;\%\) approx CCP \(= 74\;\%\) approx Therefore we can say that FCC, HCP, CCP exhibit more packing fraction or packing efficiency.
The following questions consist of two statements — Assertion (A) and Reason (R). Assertion (A) : \(Marsilea\) and ferns are referred to as cryptogams. Reason (R) : Cryptogams have inconspicuous or hidden organs. Mark the correct choice as: （ ）
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
(i) The coordinate of the point B (ii) The coordinate of the point c (iii) The point identified by the coordinates? \( \left(-3,-5\right)\) (iv) point identified by the coordinates \( \left(2,-4\right)\) (v) The abscissa of the point D (vi) The ordinate of the point H (vii) The coordinates of the point L (viii) The coordinates of the point M