Which of the following is a non-conductor in solid state but good conductor in molten state?
  • Silicon dioxide
  • Sodium
  • Diamond
  • Potassium chloride
Which of the following properties is NOT exhibited by metallic solids?
  • Low Boiling Point correct
  • Ductility
  • Electrical Conductivity
  • Malleability
Among the following solids, which one shows the strongest bonding?
  • Metallic solids
  • Covalent solids
  • Ionic solids
  • Molecular solids
Why ice is a crystalline compound?
  • Because water molecules are arranged in cage like ordered structure.
  • Because water is condensed to form solid.
  • Because ice melts to form water.
  • Because water molecules are arranged in random way.
Which of the following is a covalent crystal?
  • Ice
  • Rock salt
  • Quartz
  • Dry ice
Which of the following will melt between 500°C to 1500°C ?
  • graphite
  • salt
  • glass
  • sugar
Quartz is:
  • Covalent solid
  • Molecular solid
  • Metallic solid
  • Ionic solid
How can anyone differentiate crystalline and amorphous solids?
  • On the basis of arrangement of particles.
  • On the basis of size of particles.
  • On the basis of types of atoms.
  • On the basis of number of particles.
The intermolecular forces existing between two non polar molecules are called
  • ionic forces
  • electrostatic forces
  • London or dispersion forces
  • dipole-dipole forces
Which of the following is NOT true for solid crystals?
  • Solid crystals have fixed positions of the constituent particles.
  • Solid crystals have large intermolecular distances.
  • Solid crystals have strong intermolecular forces.
  • Solid crystals have definite mass and volume.
What will happen if sodium chloride is crystallised with a little amount of strontium chloride?
  • It will crystallize more sodium ions.
  • It will create metal deficiency.
  • It will create anionic vacancy.
  • It will create cationic vacancy.
If the anionic site is occupied by an electron and it becomes part of the lattice it is called
  • T-centre
  • F-centre
  • E-centre
  • D-centre
A p-type conductor is created on doping silicon with
  • Al correct
  • P
  • As
  • C
Which of the following is NOT correct?
  • Doping can be done with an impurity which is electron rich or electron deficient.
  • Metals conduct electricity in solid as well as molten state.
  • Molecular orbitals of the solids are close in energy to each other and form band
  • none of the above
In Schottky defect:
  • a lattice site is occupied by electron.
  • an ion occupies interstitial position between lattice points.
  • equal number of cations and anions are missing from the lattice sites.
  • the density of solid increases.
Germanium or silicon becomes semiconductor due to
  • Frenkel defect
  • Schottky defect
  • Chemical impurity
  • Metal deficiency defect
If germanium is doped with arsenic, what kind of semiconductor will be formed?
  • pn-type
  • p-type
  • n-type
  • diode
If the constituent particles are missing from lattice site the defect is called as
  • Metal Deficiency.
  • Vacancy Defect.
  • Substitutional Defect.
  • Interstitial Defect.
How many valence electrons are required in impurity, to be added to silicon, to get an an n-type semiconductor?
  • 3
  • 1
  • 2
  • 5
When can anyone observe the Schottky defect?
  • An ion leaves its normal site and occupies an interstitial site.
  • Density of the crystal is increased.
  • Equal number of cations and anions are missing from the lattice.
  • Unequal number of cations and anions are missing from the lattice.
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