Energy Bands and Semiconductors Quiz

What is the primary characteristic of the energy band in a conductor?

• Large energy gap between the valence and conduction bands

• Completely filled conduction band

• No valence band

• Overlapping of valence and conduction bands

In an insulator, the energy gap between the valence band and the conduction band is typically:

• Greater than 5 eV

• 1-3 eV

• Overlapping

• Less than 1 eV

What is the energy band gap of an intrinsic semiconductor like silicon?

• 4 eV

• 0.3 eV

• 2.5 eV

• 1.1 eV

What is thermal generation in semiconductors?

• Adding impurities to the semiconductor

• Forming a p-n junction

• Removal of free electrons by cooling

• Creation of free electrons and holes due to heating

Doping a semiconductor involves:

• Adding impurities to modify conductivity

• Increasing the energy band gap

• Cooling the material

• Removing electrons

What type of impurity is added to create an n-type semiconductor?

• Trivalent

• None of the above

• Pentavalent

• Tetravalent

In a p-type semiconductor, the majority carriers are:

• Holes

• Electrons

• None of the above

• Both electrons and holes equally

In an intrinsic semiconductor, the majority carriers are:

• Equal number of electrons and holes

• Electrons

• None of the above

• Holes

The region around a PN junction that is devoid of free charge carriers is called the:

• Saturation region

• Active region

• Conduction region

• Depletion region

The potential barrier in a PN junction is caused by:

• Random thermal motion

• Immobile ions on either side of the junction

• External voltage applied

• Drift current alone