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
Diamond is very hard because
it is covalent solid
it has large cohesive energy
high melting point
insoluble in all solvants
The following truth table belongs to which of the following four gates?
NOR
XOR
NAND
OR
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
The current gain for a transistor working as common base amplifier is 0.96. If the emitter current is 7.2 mA, then the base current is
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
Phosphorus
Aluminium
Magnesium
Both (b) and (c)
Radio waves of constant amplitude can be generated with
FET
filter
rectifier
oscillator
When a triode is used as an amplifier the phase difference between the input signal voltage and the output is
zero
To obtain a p-type germanium semiconductor, it must be doped with
phosphorus
indium
antimony
arsenic
