Diamond is very hard because
it is covalent solid
it has large cohesive energy
high melting point
insoluble in all solvants
In a junction diode, the holes are due to
protons
extra electrons
neutrons
missing electrons
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
emitter
base
collector
Any of the above depending upon the nature of transistor.
When n-type semiconductor is heated
number of electrons increases while that of holes decreases
number of electrons and holes remain same
number of electrons and holes increases equally
Transistors are
electrons - sensitive device
pressure - sensitive device
holes - sensitive device
temperature - sensitive device
The following truth table belongs to which of the following four gates?
NOR
XOR
NAND
OR
Sodium has body centred packing. If the distance between two nearest atoms is 3.7 Å, then the lattice parameter is
3.3 Å
3.9 Å
4.3 Å
4.8 Å
The transfer ratio β of a transistor is 50. The input resistance of the transistor when used in the common emitter configuration is 1kΩ. The peak value of the collector AC current for an AC input voltage of 0.01V peak is
100 μA
0.01 mA
0.25 mA
500 μA
At absolute zero, Si acts as
non-metal
metal
insulator
None of these
