27
MCQ (Single Correct Answer)
What is the coordination number in a square close packed structure in two dimensions?
A
2
B
3
C
4
D
6
28
MCQ (Single Correct Answer)
Which kind of defects are introduced by doping?
A
Dislocation defect
B
Schottky defect
C
Frenkel defect
D
Electronic defect
29
MCQ (Single Correct Answer)
Silicon doped with electron rich impurity forms ............ .
A
$p$-type semiconductor
B
n-type semiconductor
C
intrinsic semiconductor
D
insulator
30
MCQ (Single Correct Answer)
Which of the following statements is not true?
A
Paramagnetic substances are weakly attracted by magnetic field
B
Ferromagnetic substances cannot be magnetised permanently
C
The domains in antiferromagnetic substances are oppositely oriented with respect to each other
D
Pairing of electrons cancels their magnetic moment in the diamagnetic substances
31
MCQ (Single Correct Answer)
Which of the following is not true about the ionic solids?
A
Bigger ions form the close packed structure
B
Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size
C
Occupation of all the voids is not necessary
D
The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions occupying the voids