| 1 |
Which one pair belongs to acceptor impurity. |
- A. Aresincl, phosphorus
- B. Boron, gallium
- C. Arsenic, antimony
- D. Antimony, indium
|
| 2 |
Insulators have: |
- A. An empty conduction band
- B. Al full valence band
- C. A large energy gap
- D. All of above
|
| 3 |
The domain theory of magnet is important to explain the behaviour of |
- A. Diamagnets
- B. Paramagnets
- C. Ferromagnets
- D. All of these
|
| 4 |
The word amorphous means: |
- A. Regular structured
- B. Without form or structure
- C. Frozen structured
- D. None of above
|
| 5 |
After curie temperature. |
- A. Ferromagnetic
- B. Paramagnetic
- C. Magnetic
- D. Diamagnetic
|
| 6 |
Recently superconductor discovered is at temperature. |
- A. 110K
- B. 143K
- C. 16.3K
- D. 119K
|
| 7 |
Curie temperature is a point where : |
- A. Diamagnetism changes to paramagnetism
- B. Paramagnetism changes to Diamagnetism
- C. Ferromagnetism changes to paramagnetism
- D. Paramagnetism changes to Ferromagnetism
|
| 8 |
In glass, molecules are irregularly arranged so it is known as. |
- A. Solid
- B. Liquid
- C. Solid liquid
- D. Gas
|
| 9 |
At 0 K a piece of silicon is a |
- A. Conductor
- B. Semi-conductor
- C. Insulator
- D. All
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| 10 |
Semiconductors have conductivity of order: |
- A. 10<sup>-8</sup> to 10<sup>-6</sup> (Ωm)<sup>-1</sup>
- B. 10<sup>-6</sup> to 10<sup>-4</sup> (Ωm)<sup>-1</sup>
- C. 10<sup>2</sup> to 10<sup>5</sup> (Ωm)<sup>-1</sup>
- D. 10<sup>-5</sup> to 10<sup>-7</sup> (Ωm)<sup>-1</sup>
|