$NaCl$ and $C_6H_6$ exhibit which type of magnetism?

How does doping increase the conductivity of semiconductors?

In $p$-type semiconductors,the conduction of electricity is primarily due to ....

$n$-type semiconductor is formed when:

$A$ solid which is very hard,has a very high melting point in the solid state,is an insulator,and becomes a conductor of electricity in its molten state is a/an ..... solid.

Which among the following materials is extensively used as a piezoelectric material?