Which of the following conditions favours the existence of a substance in the solid-state?
Which of the following is not a characteristic of a crystalline solid?
Which of the following is an amorphous solid?
Which of the following arrangements shows schematic alignment of magnetic moments of antiferromagnetic substances?
Which of the following is true about the value of refractive index of quartz glass?
Which of the following statement is not true about amorphous solids?
The sharp melting point of crystalline solids is due to ___________.
Iodine molecules are held in the crystals lattice by ____________.
Which of the following is a network solid?
Which of the following solids is not an electrical conductor?
(A) Mg (s) (B) TiO (s)
(C) I2 (s) (D) H2O (s)
Which of the following is not the characteristic of ionic solids?
Graphite is a good conductor of electricity due to the presence of __________.
Which of the following oxides behaves as conductor or insulator depending upon temperature?
Which of the following oxides shows electrical properties like metals?
The lattice site in a pure crystal cannot be occupied by _________.
Graphite cannot be classified as __________.
Cations are present in the interstitial sites in __________.
Schottky defect is observed in crystals when __________.
Which of the following is true about the charge acquired by p-type semiconductors?
To get a n-type semiconductor from silicon, it should be doped with a substance with valence__________.
The total number of tetrahedral voids in the face centred unit cell is __________.
Which of the following point defects are shown by AgBr(s) crystals?
(A) Schottky defect
(B) Frenkel defect
(C) Metal excess defect
(D) Metal deficiency defect
In which pair most efficient packing is present?
The percentage of empty space in a body centred cubic arrangement is ________.
Which of the following statement is not true about the hexagonal close packing?
In which of the following structures coordination number for cations and anions in the packed structure will be same?
What is the coordination number in a square close packed structure in two dimensions?
Which kind of defects are introduced by doping?
Silicon doped with electron-rich impurity forms ________.
Which of the following statements is not true?
Which of the following is not true about the ionic solids?
A ferromagnetic substance becomes a permanent magnet when it is placed in a magnetic field because ________.
The correct order of the packing efficiency in different types of unit cells is ________.
Which of the following defects is also known as dislocation defect?
In the cubic close packing, the unit cell has ________.
The edge lengths of the unit cells in terms of the radius of spheres constituting fcc, bcc and simple cubic unit cell are respectively________.
Which of the following represents correct order of conductivity in solids?
Which of the following is not true about the voids formed in 3 dimensional hexagonal close packed structure?
The value of magnetic moment is zero in the case of antiferromagnetic substances because the domains ________.
Which of the following statements are not true?
Which of the following statements are true about metals?
Under the influence of electric field, which of the following statements is true about the movement of electrons and holes in a p-type semi-conductor?
Which of the following statements are true about semiconductors?
An excess of potassium ions makes KCl crystals appear violet or lilac in colour since ________.
The number of tetrahedral voids per unit cell in NaCl crystal is ________.
Amorphous solid can also be called ________.
A perfect crystal of silicon (Fig. 1.1) is doped with some elements as given in the options. Which of these options show n-type semiconductors?
Which of the following statements are correct?
Which of the following features are not shown by quartz glass?
Which of the following cannot be regarded as molecular solid?
In which of the following arrangements octahedral voids are formed?
Frenkel defect is also known as ________.
Which of the following defects decrease the density?
Why are liquids and gases categorized as fluids?
Why are solids incompressible?
Inspite of long range order in the arrangement of particles why are the crystals usually not perfect?
Why does table salt, NaCl sometimes appear yellow in colour?
Why is FeO (s) not formed in stoichiometric composition?
Why does white ZnO (s) becomes yellow upon heating?
Why does the electrical conductivity of semiconductors increase with rise in temperature?
Explain why does conductivity of germanium crystals increase on doping with galium.
In a compound, nitrogen atoms (N) make cubic close packed lattice and metal atoms (M) occupy one-third of the tetrahedral voids present. Determine the formula of the compound formed by M and N?
Under which situations can an amorphous substance change to crystalline form?
Match the defects given in Column I with the statements in given Column II.
Match the type of unit cell given in Column I with the features given in Column II.
Match the types of defect given in Column I with the statement given in Column II.
Match the items given in Column I with the items given in Column II.
Match the type of packing given in Column I with the items given in Column II.
Note : In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
With the help of a labelled diagram show that there are four octahedral voids per unit cell in a cubic close packed structure.
Show that in a cubic close packed structure, eight tetrahedral voids are present per unit cell.
How does the doping increase the conductivity of semiconductors?
A sample of ferrous oxide has actual formula Fe0.93O1.00. In this sample what fraction of metal ions are Fe2+ ions? What type of nonstoichiometric defect is present in this sample?
