In P-type semiconductor, the majority and minority charge carriers are respectively

(1) Protons and electrons

(2) Electrons and protons

(3) Electrons and holes

(4) Holes and electrons

In intrinsic semiconductor at room temperature, the number of electrons and holes are

(1) Equal

(2) Zero

(3) Unequal

(4) Infinite

The impurity atom added to germanium to make it an N-type semiconductor is 

(1) Arsenic

(2) Iridium

(3) Aluminium

(4) Iodine

In a semiconductor, the separation between the conduction band and valence band is of the order of

(1) 100 eV

(2) 10 eV

(3) 1 eV

(4) 0 eV

In a good conductor, the energy gap between the conduction band and the valence band is:
1. Infinite
2. Wide
3. Narrow
4. Zero

A semiconductor is cooled from ${\mathrm{T}}_1\mathrm{K}$ to ${\mathrm{T}}_2\mathrm{K}$. Its resistance

(1) Will decrease

(3) Will increase

(3) Will first decrease and then increase

(4) Will not change

The intrinsic semiconductor becomes an insulator at

(1) $0°\mathrm{C}$

(2) $-100°\mathrm{C}$ 

(3)  300 K

(4) 0 K

At zero Kelvin a piece of germanium

(1) Becomes semiconductor

(2) Becomes good conductor

(3) Becomes bad conductor

(4) Has maximum conductivity

When N-type of semiconductor is heated

(1) Number of electrons increases while that of holes decreases

(2) Number of holes increases while that of electrons decreases

(3) Number of electrons and holes remains same

(4) Number of electrons and holes increases equally