Select the correct option based on statements below:
Assertion (A): | LiCl shows pink colour when heated in presence of lithium vapours. |
Reason (R): | LiCl shows Frenkel defect. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Select the correct option based on statements below:
Assertion (A): | In an hcp structure, each sphere is surrounded by eight other spheres. |
Reason (R): | ABC, ABC ................................ represents hcp structure. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Select the correct option based on statements below:
Assertion (A): | Due to Frenkel defect, the density of the crystalline solid decreases. |
Reason (R): | In Frenkel defect cation and anion leave the crystal. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Select the correct option based on statements below:
Assertion (A): | The stability of a crystal is reflected by the magnitude of its melting point. |
Reason (R): | Greater the intermolecular forces of attraction, the higher will be the stability and melting point of the substance. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Incorrect(s) statement among the following:
I. | Vacancy defect results in a decrease in the density of the substance. |
II. | Interstitial defects results in an increase in the density of the substance. |
III. | Impurity defect has no effect on the density of the substance. |
IV. | Frenkel defect results in an increase in the density of the substance. |
1. (I, II)
2. (II, III)
3, (III, IV)
4. (I, IV)
The correct statements among the following about metals are-
I. | Valence band overlaps with the conduction band. |
II. | The gap between the valence band and conduction band is negligible |
III. | The gap between the valence band and conduction band cannot be determined |
IV. | Valence band may remain partially filled |
1. (I, II, III)
2. (II, III, IV)
3. (I, III, IV)
4. (I, II, IV)
Under the influence of the electric field, which of the following statement is true about the movement of electrons and holes in a p-type semiconductor?
I. | Electron will move towards the positively charged plate through electron holes |
II. | Holes will appear to be moving towards the negatively charged plate |
III. | Both electrons and holes appear to move towards the positively charged plate |
IV. | Movement of electrons is not related to the movement of holes |
The correct choice among the given is-
1. (I, II)
2. (II, III)
3. (III, IV)
4. (I, IV)
Consider the following statements about semiconductors.
I. | Silicon doped with electron-rich impurity is a p-type semiconductor. |
II. | Silicon doped with an electron-rich impurity is an n-type semiconductor. |
III. | Delocalised electrons increase the conductivity of doped silicon. |
IV. | An electron vacancy increases the conductivity of n-type semiconductor. |
1. I and II
2. II and III
3. III and IV
4. I and IV
Which of the following statements is correct?
I. | Ferrimagnetic substances lose ferrimagnetism on heating and become paramagnetic |
II. | Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic |
III. | Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not canceled by each other |
IV. | In ferromagnetic substances, all the domains get oriented in the direction of the magnetic field and remain as such even after removing the magnetic field |
1. (I, II)
2. (II, III)
3. (III, IV)
4. (I, IV)
Match the defects given in Column I with the statements given in Column II.
Column I | Column II |
A. Simple vacancy defect | 1. Shown by non-ionic solids and increases the density of the solid |
B. Simple interstitial defect | 2. Shown by ionic solids and decreases the density of the solid |
C. Frenkel defect | 3. Shown by non-ionic solids and decreases the density of the solid |
D. Schottky defect | 4. Shown by ionic solids and density of the solid remains the same |
Codes
A | B | C | D | |
1. | 3 | 1 | 4 | 2 |
2. | 1 | 2 | 3 | 4 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |