Electronic Devices Test -11

P-N junction diode allows the minority charge carriers. The positive terminal of the battery pushes the holes (minority carriers) towards the p-type semiconductor. In the similar way, negative terminal of the battery pushes the free electrons (minority carriers) towards the n-type semiconductor.
The positive charge carriers (holes) which cross the p-n junction are attracted towards the negative terminal of the battery. On the other hand, the negative charge carriers (free electrons) which cross the p-n junction are attracted towards the positive terminal of the battery. Thus, the minority charge carriers carry the electric current in reverse biased p-n junction diode.

The resistance of silicon (a semiconductor) increases on decrease of temperature. At absoute zero, it will behave like an insulator.

In crystalline solids, atoms are arranged in a definite geometrical shape. They are anisotropic i.e. their physical properties such as thermal conductivity/resistance is different in different directions.

Conductivity of intrinsic semiconductors is increased by adding an appropriate amount of suitable impurity. This process is called doping.

In case of insulating material, there exists a large forbidden gap in between the conduction band and the valence band. The forbidden gap is very wide, approximately greater than 3 eV in insulators. For a diamond, which is an insulator, the forbidden gap is about 6 eV.