A semiconducting device is connected in a series in circuit with a battery and a resistance. A current is allowed to pass through the circuit. If the polarity of the battery is reversed, the current drios to almost zero. The device may be
a p-n junction
an intrinsic semiconductor
a p-type semiconductor
an n-type semiconductor
Diamond is very hard because
it is covalent solid
it has large cohesive energy
high melting point
insoluble in all solvants
Transistors are
electrons - sensitive device
pressure - sensitive device
holes - sensitive device
temperature - sensitive device
Sodium has body centred packing. Distance between two nearest atoms is 3.7Å. The lattice parameter is
6.8Å
4.3Å
3.0Å
8.6Å
Phosphorus
Aluminium
Magnesium
Both (b) and (c)
In a junction diode, the holes are due to
protons
extra electrons
neutrons
missing electrons
The following truth table belongs to which of the following four gates?
NOR
XOR
NAND
OR
n-type semiconductor
p-type semiconductor
n-type conductor
insulator
To obtain a p-type germanium semiconductor, it must be doped with
phosphorus
indium
antimony
arsenic
At absolute zero, Si acts as
non-metal
metal
None of these