| 1 |
In the doping process, the ratio of the doping atoms to the semi-conductor atom is |
1 to 10
1 to 10<sup>3</sup>
1 to 10<sup>6</sup>
1 to 10<sup>9</sup>
|
| 2 |
When small number of atoms from some other suitable element is added to the semi-conductor material, then this process is known as |
impurification
adding
doping
extrinsivity
|
| 3 |
A semi conductor in its extremely pure from is known as |
extrinsic semi-conductor
intrinsic semi-conductor
either of them
none of them
|
| 4 |
Conductors are those materials in which energy gap is |
very large (several eV)
very narrow (= 1eV)
either of them
none of them
|
| 5 |
Insulators are those material in which energy gap is |
very large (several eV)
very narrow (= 1ev)
either of them
none of them
|
| 6 |
The materials in which there are plenty of free electrons for electrical conduction are known as |
conductors
insulators
semi-conductors
all of them
|
| 7 |
The materials in which valence electrons are bound very tightly to their atoms and are not free, are known as |
conductors
insulators
semi-conductors
all of them
|
| 8 |
The bands below the valence band are |
completely filled and play active part in conduction process
completely filled and plays no part in conduction process
not completely filled and play active part in conduction process
not completely filled and play no part in conduction process
|
| 9 |
The conduction band in a solid |
may be empty
cannot be empty
should be filled
all of them
|
| 10 |
The electrons occupying the conduction band are known as |
conduction electrons
free electrons
both of them
none of them
|
| 11 |
The band above the valence band is called |
high energy band
conduction band
empty band
none of them
|
| 12 |
The valence band of an atom in a solid |
is always empty
may or may not be empty
can never be empty
none of them
|
| 13 |
When a large number of atoms are brought close to one another to form a solid, each energy level of an isolated atom splits into sub-levels, called |
energy bands
energy shells
states
all of them
|
| 14 |
Electrons of an isolated atom are bound to the nucleus, and? |
can only have distinct energy level
can only have same energy level
may or may not have distinct energy
none of them
|
| 15 |
Which of the following theory completely explain the three types of materials? |
Bohr model of electron distribution
Rutherford atomic model
Pauli's exclusion principle
energy band theory
|
| 16 |
The electrical conductivities of insulators are ranging from |
10<sup>-5</sup>to 10<sup>-10 </sup>(<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)</b><sup>-1</sup></span>
10<sup>-10</sup>to 10<sup>-15</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)</b><sup>-1</sup></span>
10<sup>-5</sup>to 10<sup>-15</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)</b><sup>-1</sup></span>
10<sup>-10</sup>to 10<sup>-20</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)</b><sup>-1</sup></span>
|
| 17 |
Metals are good conductors of electricity and their conductivities are of the order of |
10<sup>3</sup>(<span style="color: rgb(34, 34, 34); font-family: "Times New Roman"; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)<sup>-1</sup></b></span>
10<sup>4</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)<sup>-1</sup></b></span>
10<sup>6</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)<sup>-1</sup></b></span>
10<sup>7</sup>(<span style="font-family: "Times New Roman"; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);"><b>Ω m)<sup>-1</sup></b></span>
|
| 18 |
Lead, copper and wrought iron are examples of |
brittle substances
ductile substances
plastic substances
elastic substances
|
| 19 |
Glass and high carbon steel are the examples of |
brittle substances
ductile substances
plastic substances
elastic substances
|
| 20 |
The substances which break just after the elastic limit is reached, are known as |
brittle substances
ductile substances
plastic substances
elastic substances
|