To a germanium sample, traces of gallium are added as an impurity. The resultant sample would behave like

(a) A conductor
(b) A P-type semiconductor
(c) An N-type semiconductor
(d) An insulator

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Donor type impurity is found in
(a) Trivalent elements       (b) Pentavalent elements
(c) In both the above        (d) None of these

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the

(a) Variation of scattering mechanism with temperature

(b) Crystal structure

(c) Variation of the number of charge carriers with temperature

(d) Type of bond

Concept Questions :-

Types of semiconductors

Difficulty Level:

The charge on a hole is equal to the charge of

(a) Zero               (b) Proton
(c) Neutron          (d) Electron

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A Ge specimen is doped with Al. The concentration of acceptor atoms is . Given that the intrinsic concentration of electron hole pairs is $~{10}^{19}/{\mathrm{m}}^{3}$, the concentration of electrons in the specimen is
(a) ${10}^{17}/{\mathrm{m}}^{3}$         (b) ${10}^{15}/{\mathrm{m}}^{3}$
(c) ${10}^{4}/{\mathrm{m}}^{3}$           (d) ${10}^{2}/{\mathrm{m}}^{3}$

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Which of the following has negative temperature coefficient of resistance
(a) Copper               (b) Aluminium
(c) Iron                   (d) Germanium

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In semiconductors at a room temperature

(a) The valence band is partially empty and the conduction band is partially filled

(b) The valence band is completely filled and the conduction band is partially filled

(c) The valence band is completely filled

(d) The conduction band is completely empty

Concept Questions :-

Energy band theory
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Regarding a semiconductor which one of the following is wrong

(a) There are no free electrons at room temperature

(b) There are no free electrons at 0 K

(c) The number of free electrons increases with rise of temperature

(d) The charge carriers are electrons and holes

Concept Questions :-

Types of semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Which of the following statements is true for an N-type semi-conductor

(a) The donor level lies closely below the bottom of the conduction band

(b) The donor level lies closely above the top of the valence band

(c) The donor level lies at the halfway mark of the forbidden energy gap

(d) None of above

Concept Questions :-

Types of semiconductors

Difficulty Level:

Choose the correct statement

(a) When we heat a semiconductor its resistance increases
(b) When we heat a semiconductor its resistance decreases
(c) When we cool a semiconductor to 0 K then it becomes super conductor
(d) Resistance of a semiconductor is independent of temperature

Concept Questions :-

Types of semiconductors