Semiconductors: Properties, Applications, and Exam Preparation

Question 1

Which of the following is a defining characteristic of semiconductor materials?

Accepted Answer

Low electrical conductivity at room temperature but can conduct electricity under specific conditions

Answer

High thermal conductivity

Answer

Metallic luster

Answer

High melting point

Question 2

The energy gap in a semiconductor material:

Accepted Answer

Represents the energy difference between the valence band and the conduction band

Answer

Is always smaller than 1 eV

Answer

Solely determines the electrical conductivity of the material

Answer

Remains constant regardless of temperature

Question 3

The junction formed between a p-type and an n-type semiconductor is known as a:

Accepted Answer

p-n junction

Answer

n-p junction

Answer

Metal-semiconductor junction

Answer

Insulator-semiconductor junction

Question 4

Which of the following electronic devices utilizes the unique properties of semiconductors?

Accepted Answer

Transistors

Answer

Capacitors

Answer

Resistors

Answer

Inductors

Question 5

The increase in carrier concentration in semiconductors with rising temperature is primarily attributed to:

Accepted Answer

Generation of electron-hole pairs

Answer

Thermal excitation of electrons

Answer

Ionization of impurities

Answer

Diffusion of carriers

Question 6

The conversion of light energy into electrical energy in semiconductors is referred to as:

Accepted Answer

Photovoltaics

Answer

Photoconduction

Answer

Electroluminescence

Answer

Thermoelectricity

Question 7

In the band theory of semiconductors, which band contains the outermost electrons?

Accepted Answer

Valence band

Answer

Core band

Answer

Conduction band

Question 8

How do intrinsic and extrinsic semiconductors differ?

Accepted Answer

Extrinsic semiconductors are formed by adding impurities to intrinsic semiconductors, modifying their electrical properties.

Answer

Intrinsic semiconductors have a higher carrier concentration than extrinsic semiconductors.

Answer

The conductivity of intrinsic semiconductors is unaffected by temperature.

Answer

Extrinsic semiconductors can only exhibit n-type behavior.

Question 9

A p-type semiconductor is formed by:

Accepted Answer

Adding acceptor impurities

Answer

Adding donor impurities

Answer

Illuminating the semiconductor with light

Answer

Heating the semiconductor to a high temperature

Question 10

The mobility of charge carriers in a semiconductor is defined as:

Accepted Answer

The ratio of the drift velocity to the electric field

Answer

The average velocity of charge carriers

Answer

The drift velocity of charge carriers in an electric field

Answer

The ratio of the thermal velocity to the electric field

Question 11

The technique used to create a thin layer of semiconductor material on a substrate is called:

Accepted Answer

Epitaxy

Answer

Diffusion

Answer

Ion implantation

Answer

Annealing

Question 12

The fundamental property that differentiates semiconductors from metals and insulators is:

Accepted Answer

Variable electrical conductivity

Answer

High thermal conductivity

Answer

Low mechanical strength

Answer

High refractive index

Question 13

Which of the following materials is a metallic conductor? A material with a continuous band of energy states that allows electrons to move freely.

Accepted Answer

Metallic conductor

Answer

Semiconductor

Question 14

In an intrinsic semiconductor, the concentration of electrons is equal to the concentration of what?

Accepted Answer

Holes

Answer

Photons

Answer

Ions

Answer

Dopants

Question 15

Which of the following technologies directly utilizes the semiconducting properties of materials?

Accepted Answer

Solar cells

Answer

Capacitors

Answer

Optical fibers

Answer

Superconductors

Question 16

The energy difference between the valence band and the conduction band in a semiconductor is known as the:

Accepted Answer

Band gap

Answer

Ionization energy

Answer

Fermi level

Answer

Activation energy

Question 17

The process of intentionally introducing impurities into a semiconductor to modify its electrical properties is called:

Accepted Answer

Doping

Answer

Annealing

Answer

Tempering

Answer

Alloying

Question 18

What is a key advantage of using semiconductors in electronic devices?

Accepted Answer

Controllable electrical conductivity

Answer

High thermal stability

Answer

High mechanical strength

Answer

Low melting point

Question 19

The mobility of charge carriers in a semiconductor is primarily influenced by:

Accepted Answer

Temperature and the presence of impurities

Answer

Electric field only

Answer

Magnetic field only

Question 20

Which statement accurately describes a p-type semiconductor?

Accepted Answer

Holes are the majority charge carriers

Answer

The Fermi level lies close to the conduction band

Answer

Electrons are the majority charge carriers

Answer

Electrical conductivity decreases with increasing temperature

Question 21

The phenomenon of light emission in a semiconductor caused by the recombination of charge carriers is known as:

Accepted Answer

Electroluminescence

Answer

Triboluminescence

Answer

Chemiluminescence

Answer

Photoluminescence