46
MCQ (Multiple Correct Answer)
Amorphous solids can also be called ............ .
A
pseudo solids
B
true solids
C
super cooled liquids
D
super cooled solids
47
MCQ (Multiple Correct Answer)
A perfect crystal of silicon (fig) is doped with some elements as given in the options. Which of these options shows n-type semiconductors?
A
B
C
D
48
MCQ (Multiple Correct Answer)
Which of the following statements are correct?
A
Ferrimagnetic substances lose ferrimagnetism on heating and become paramagnetic
B
Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic
C
Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not cancelled by each other
D
In ferromagnetic substances, all the domains get oriented in the direction of magnetic field and remain as such even after removing magnetic field
49
MCQ (Multiple Correct Answer)
Which of the following features are not shown by quartz glass?
A
This is a crystalline solid
B
Refractive index is same in all the directions
C
This has definite heat of fusion
D
This is also called super cooled liquid
50
MCQ (Multiple Correct Answer)
Which of the following cannot be regarded as molecular solid?
A
SiC (silicon carbide)
B
AIN
C
Diamond
D
$\mathrm{I}_2$