Semicon
Questions and Answers
- 1.
The diffused impurities with three valence electrons are called _______
- A.
Acceptor atoms
- B.
Donor atoms
- C.
Hole
- D.
Fre electrons
Correct Answer
A. Acceptor atomsExplanation
Acceptor atoms are diffused impurities with three valence electrons. These atoms have an electron deficiency and can accept an extra electron from the surrounding material, creating a positive charge. This property makes them useful in the creation of p-type semiconductors, where they contribute to the formation of electron holes, which play a crucial role in the conduction of electric current.Rate this question:
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- 2.
What type of materials has very large number of free electrons and conducts current very well?
- A.
Insulators
- B.
Semiconductors
- C.
Conductors
- D.
Crystals
Correct Answer
C. ConductorsExplanation
Conductors are materials that have a very large number of free electrons and conduct current very well. These materials have electrons that are loosely bound to their atoms, allowing them to move freely and carry electric charge. This high number of free electrons enables conductors to easily conduct electricity, making them ideal for applications such as electrical wiring and circuitry.Rate this question:
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- 3.
What is the most widely used semiconductor material?
- A.
Germanium
- B.
GaAs
- C.
Silicon
- D.
Boron
Correct Answer
C. SiliconExplanation
Silicon is the most widely used semiconductor material due to its abundance, affordability, and excellent electrical properties. It is a fundamental component of almost all modern electronic devices, including microchips, transistors, and solar cells. Silicon's ability to efficiently conduct electricity and its compatibility with existing manufacturing processes have made it the preferred choice for the semiconductor industry. Germanium and GaAs are also used in specific applications, but silicon dominates the market due to its superior overall performance and cost-effectiveness. Boron, on the other hand, is not commonly used as a semiconductor material.Rate this question:
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- 4.
What do you call materials containing more than one element such as GaAs, AlAs or GaP?
- A.
Multiple semiconductor
- B.
Elemental semiconductor
- C.
Compound semiconductor
- D.
Extrinsic semiconductor
Correct Answer
C. Compound semiconductorExplanation
Compound semiconductors are materials that consist of two or more elements. They are formed by combining different elements, such as GaAs, AlAs, or GaP. These materials have unique electronic properties that make them suitable for various applications in electronics and optoelectronics. Unlike elemental semiconductors, which are made up of a single element, compound semiconductors offer a wider range of possibilities for controlling and manipulating their electrical characteristics. Therefore, the term "compound semiconductor" accurately describes materials containing more than one element.Rate this question:
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- 5.
What is the smallest particle that retains the characteristics of its element?
- A.
Atom
- B.
Matter
- C.
Electron
- D.
Compound
Correct Answer
A. AtomExplanation
An atom is the smallest particle that retains the characteristics of its element. Atoms are composed of protons, neutrons, and electrons. Protons have a positive charge, neutrons have no charge, and electrons have a negative charge. The number of protons in an atom determines its atomic number and defines the element. The arrangement and number of electrons in an atom determine its chemical properties. Therefore, atoms are the fundamental building blocks of matter and retain the unique characteristics of their respective elements.Rate this question:
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- 6.
What is the basic particle of negative electrical charge?
- A.
Proton
- B.
Neutron
- C.
Ion
- D.
Electron
Correct Answer
D. ElectronExplanation
The basic particle of negative electrical charge is the electron. Electrons are subatomic particles that orbit around the nucleus of an atom. They carry a negative charge and are responsible for the flow of electricity. Protons carry a positive charge, neutrons are neutral, and ions can carry either a positive or negative charge depending on the number of electrons they have gained or lost.Rate this question:
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- 7.
The mass of proton is __________ times the mass of electron.
- A.
1836
- B.
1840
- C.
1839
- D.
1740
Correct Answer
A. 1836Explanation
The mass of a proton is 1836 times the mass of an electron. This means that a proton is significantly heavier than an electron. The mass of an electron is very small compared to the mass of a proton, and this difference in mass is a fundamental property of these subatomic particles.Rate this question:
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- 8.
The mass of neutron is __________ times the mass of electron.
- A.
1836
- B.
1839
- C.
1983
- D.
1964
Correct Answer
B. 1839Explanation
The mass of a neutron is 1839 times the mass of an electron.Rate this question:
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- 9.
What is the charge of the proton?
- A.
+ 1.602 x 10^-19
- B.
+ 1.602 x 10^-18
- C.
+ 1.602 x 10^-20
- D.
+ 1.602 x 10^-21
Correct Answer
A. + 1.602 x 10^-19Explanation
The charge of the proton is +1.602 x 10^-19. This value represents the elementary charge, which is the fundamental unit of electric charge. Protons are positively charged particles found in the nucleus of an atom. They have a charge equal in magnitude but opposite in sign to the electron's charge. The given answer is the correct value for the charge of a proton, expressed in scientific notation.Rate this question:
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- 10.
Which one is electrically neutral?
- A.
Electron
- B.
Proton
- C.
Neutron
- D.
Ion
Correct Answer
C. NeutronExplanation
A neutron is electrically neutral because it has no charge. Unlike electrons, which have a negative charge, and protons, which have a positive charge, neutrons have a neutral charge. This means that the number of positively charged protons in an atom is balanced by the number of negatively charged electrons, with neutrons adding no additional charge. Therefore, a neutron does not contribute to the overall electrical charge of an atom or molecule, making it electrically neutral.Rate this question:
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- 11.
THe nucleus of an atom is composed of
- A.
Proton and electron
- B.
Neutron and electron
- C.
Proton and neutron
- D.
Ions and electrons
Correct Answer
C. Proton and neutronExplanation
The nucleus of an atom is composed of protons and neutrons. Protons have a positive charge, while neutrons have no charge. These two particles are tightly packed together in the center of the atom, forming the nucleus. Electrons, on the other hand, are negatively charged particles that orbit around the nucleus in specific energy levels. Ions are atoms or molecules that have gained or lost electrons, resulting in a positive or negative charge. Therefore, the correct answer is proton and neutron.Rate this question:
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- 12.
An electron in the outermost shell of an atom is called
- A.
Valance electrons
- B.
Hole
- C.
Free electrons
- D.
Shell electron
Correct Answer
A. Valance electronsExplanation
Valence electrons are the electrons present in the outermost shell of an atom. These electrons are involved in the formation of chemical bonds and determine the reactivity and chemical properties of an element. They are responsible for the atom's ability to gain, lose, or share electrons with other atoms, thus forming compounds. Valence electrons play a crucial role in understanding the behavior of elements in chemical reactions and their ability to form stable compounds.Rate this question:
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- 13.
What is the mass of electron in grams?
- A.
1.675 x 10^-24
- B.
1.672 x 10^-18
- C.
7.109 x 10^-28
- D.
9.107 x 10^-28
Correct Answer
D. 9.107 x 10^-28Explanation
The mass of an electron is extremely small, and it is typically measured in kilograms or atomic mass units (amu). However, in this question, the mass of the electron is given in grams. Among the given options, the correct answer is 9.107 x 10^-28 grams.Rate this question:
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- 14.
The atomic number of an atom is determined by the number of _______ in the nucleus.
- A.
Protons
- B.
Neutrons
- C.
Ions
- D.
Electrons
Correct Answer
A. ProtonsExplanation
The atomic number of an atom is determined by the number of protons in the nucleus. This is because the atomic number represents the number of protons in an atom, which determines its identity and place on the periodic table. The number of neutrons, ions, and electrons may vary in an atom, but the number of protons remains constant for a specific element.Rate this question:
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- 15.
When a neutral atom losses an electron, the atom becomes ______.
- A.
Negative ion
- B.
Positive ion
- C.
Hole
- D.
Neutral ion
Correct Answer
B. Positive ionExplanation
When a neutral atom loses an electron, it results in a positive ion. This is because the atom now has more protons than electrons, giving it a net positive charge. The loss of an electron creates an imbalance in the atom's charge, leading to a positive ion formation.Rate this question:
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- 16.
When a neutral atom gains an electron, the atom becomes _______/
- A.
Negative ion
- B.
Positive ion
- C.
Hole
- D.
Neutral ion
Correct Answer
A. Negative ionExplanation
When a neutral atom gains an electron, it becomes a negative ion. This is because the atom now has more electrons than protons, resulting in a net negative charge. The extra electron(s) added to the atom creates an imbalance in the positive and negative charges, making it negatively charged.Rate this question:
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- 17.
A __________ is one that has acquired enough energy to break away from the valence band of the parent atom.
- A.
Valence electron
- B.
Free electron
- C.
Hole
- D.
Shell electron
Correct Answer
B. Free electronExplanation
A free electron is one that has acquired enough energy to break away from the valence band of the parent atom. When an electron gains sufficient energy, it can overcome the attractive forces of the nucleus and become detached from its parent atom. This allows the electron to move freely within the material, making it a free electron. Free electrons play a crucial role in various physical phenomena, such as electrical conductivity and the behavior of semiconductors.Rate this question:
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- 18.
An atom has discrete bands of energy called
- A.
Electrons
- B.
Shells
- C.
Crystals
- D.
Packets
Correct Answer
B. ShellsExplanation
An atom has discrete bands of energy called shells. Shells are the regions surrounding the nucleus of an atom where electrons can be found. These shells are organized into different energy levels, with each level capable of holding a specific number of electrons. The electrons occupy the shells in a specific order, with the innermost shell being filled first before moving on to the outer shells. The concept of shells helps explain the arrangement and behavior of electrons in an atom.Rate this question:
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- 19.
According to the classical ______, the atom is viewed as having a planetary-type structure with electrons orbiting at various distances around the central nucleus.
- A.
Mohr circle
- B.
Bohr model
- C.
Characteristic curve
- D.
Kepler's law
Correct Answer
B. Bohr modelExplanation
The correct answer is the Bohr model. The Bohr model is a representation of the atom that suggests electrons orbit the nucleus in specific energy levels or shells. This model was proposed by Niels Bohr in 1913 and is based on the principles of quantum mechanics. It was an important development in understanding atomic structure and helped explain the stability of atoms and the emission and absorption of light.Rate this question:
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- 20.
What do you call single element semiconductor materials such as silicon and germanium?
- A.
Unit semiconductor
- B.
Elemental semiconductor
- C.
Compound semiconductor
- D.
Extrinsic semiconductor
Correct Answer
B. Elemental semiconductorExplanation
Single element semiconductor materials such as silicon and germanium are called elemental semiconductors. This is because they consist of a single element in their pure form and exhibit semiconductor properties, meaning they can conduct electricity under certain conditions. These materials are widely used in electronic devices and integrated circuits due to their ability to control and manipulate electrical currents.Rate this question:
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- 21.
WHat type of material have very few free electrons and do not conduct current at all?
- A.
Insulators
- B.
Semiconductors
- C.
Conductors
- D.
Crystals
Correct Answer
A. InsulatorsExplanation
Insulators are materials that have very few free electrons and do not conduct current at all. Unlike conductors, which have a high number of free electrons that can easily move and carry electric charge, insulators have tightly bound electrons that are not able to move freely. This lack of free electrons makes it difficult for electric current to flow through insulators, resulting in their non-conductive properties. Semiconductors, conductors, and crystals, on the other hand, have varying degrees of electron mobility and conductivity.Rate this question:
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- 22.
Semiconductor atoms bond together to form a solid material called _____________
- A.
Lattice
- B.
Quartz
- C.
Crystal
- D.
Carbon
Correct Answer
C. CrystalExplanation
Semiconductor atoms bond together to form a solid material called a crystal. A crystal is a regular, repeating arrangement of atoms, ions, or molecules in a three-dimensional pattern. In a crystal lattice, the atoms are arranged in a highly ordered structure, which gives the material its characteristic properties. Crystals have a unique arrangement of atoms that allows them to have specific electrical, optical, and mechanical properties, making them essential for various technological applications, including electronics and photonics.Rate this question:
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- 23.
What do you call the bonds that hold the crystals together?
- A.
Ionic bond
- B.
Mighty bond
- C.
Semicon bond
- D.
Covalent bond
Correct Answer
D. Covalent bondExplanation
Covalent bonds are the type of bonds that hold crystals together. In a covalent bond, atoms share electrons, resulting in a strong bond between them. This type of bond is commonly found in non-metallic elements and compounds. Ionic bonds involve the transfer of electrons, whereas covalent bonds involve the sharing of electrons. Mighty bond and semicon bond are not recognized terms for describing bonds.Rate this question:
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- 24.
When an electron breaks away to become free, it leaves a hole in the valence band creating what is known as ___________.
- A.
A hole pair
- B.
Recombination
- C.
Hole current
- D.
Electron-hole pair
Correct Answer
D. Electron-hole pairExplanation
When an electron breaks away from the valence band, it leaves behind a positively charged "hole" in the valence band. This hole can attract and bind another electron, forming an electron-hole pair. Therefore, the correct answer is "electron-hole pair."Rate this question:
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- 25.
How are electon-hole pairs produced?
- A.
Thermally
- B.
By doping
- C.
By covalent bonding
- D.
By recombination
Correct Answer
A. ThermallyExplanation
Electron-hole pairs are produced thermally when thermal energy is absorbed by a material, causing an electron to move from the valence band to the conduction band, leaving behind a positively charged hole in the valence band. This process occurs in certain semiconductors or insulators at high temperatures, where the thermal energy is sufficient to promote electrons to higher energy levels. Doping, covalent bonding, and recombination are not direct mechanisms for the production of electron-hole pairs.Rate this question:
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- 26.
A free electon will eventually lose energy and fall back into a hole. This is called ___________.
- A.
Bonding
- B.
Crystallization
- C.
Recombination
- D.
Doping
Correct Answer
C. RecombinationExplanation
Recombination refers to the process in which a free electron loses energy and falls back into a hole. This occurs when an electron in a higher energy state combines with a hole (an empty state in the valence band) in a lower energy state, resulting in the recombination of the electron-hole pair. This process is important in semiconductors and plays a crucial role in the functioning of devices such as transistors and solar cells.Rate this question:
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- 27.
What type of current occurs as valance electrons move from hole to hole creating, in effect, a movement of holes in the opposite direction?
- A.
Drift current
- B.
Diffused current
- C.
Election current
- D.
Hole current
Correct Answer
D. Hole currentExplanation
Hole current occurs when valence electrons move from hole to hole, creating a movement of holes in the opposite direction. This phenomenon is commonly observed in semiconductors, where the absence of an electron in the valence band is treated as a positively charged particle called a hole. As electrons move from one hole to another, it appears as if the holes themselves are moving in the opposite direction, resulting in hole current.Rate this question:
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- 28.
What is the process of adding pentavalent or trivalent impurities to semiconductors?
- A.
Drifting
- B.
Recombination
- C.
Doping
- D.
Bonding
Correct Answer
C. DopingExplanation
Doping is the process of intentionally adding impurities, such as pentavalent or trivalent elements, to semiconductors. This is done to modify the electrical properties of the semiconductor material, such as its conductivity. The added impurities introduce extra electrons or holes into the semiconductor lattice, which can increase or decrease its conductivity, depending on the type of impurity added. Doping is a crucial technique in semiconductor manufacturing, as it allows for the creation of different types of semiconductor devices with specific electrical characteristics.Rate this question:
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- 29.
What is created by adding impurity atoms with three valence electrons?
- A.
P-type semiconductor
- B.
Hole
- C.
N-type semiconductor
- D.
Ionized semiconductor
Correct Answer
A. P-type semiconductorExplanation
When impurity atoms with three valence electrons are added to a semiconductor, it creates a p-type semiconductor. In this type of semiconductor, the impurity atoms (also known as acceptor atoms) create "holes" in the crystal lattice structure. These holes act as positive charge carriers, allowing for the movement of positive charges within the material. This results in a material with an excess of positive charge carriers (holes) and a deficiency of negative charge carriers (electrons), hence creating a p-type semiconductor.Rate this question:
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- 30.
What is created by adding impurity atoms with five valence electrons?
- A.
P-type semiconductor
- B.
Hole
- C.
N-type semiconductor
- D.
Ionized semiconductor
Correct Answer
C. N-type semiconductorExplanation
When impurity atoms with five valence electrons are added to a semiconductor, they create an excess of electrons in the material. This results in the formation of an n-type semiconductor. In an n-type semiconductor, the impurity atoms provide additional electrons that are free to move within the crystal lattice, increasing its conductivity. This excess of electrons is responsible for the n in n-type semiconductor.Rate this question:
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- 31.
What do you call impurites with five valence electrons?
- A.
Trivalent
- B.
Pentavalent
- C.
Quadvalent
- D.
Covalent
Correct Answer
B. PentavalentExplanation
Pentavalent refers to impurities with five valence electrons. In chemistry, valence electrons are the outermost electrons in an atom that participate in chemical bonding. Pentavalent impurities have five electrons in their outermost shell, allowing them to form bonds with other atoms by sharing or transferring electrons. This term is commonly used to describe elements or compounds that exhibit this valence state, indicating their ability to form five bonds in chemical reactions.Rate this question:
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- 32.
What are majority carriers in an n-type semiconductor?
- A.
Free electrons
- B.
Valance electrons
- C.
Holes
- D.
Protons
Correct Answer
A. Free electronsExplanation
In an n-type semiconductor, majority carriers are free electrons. N-type semiconductors are doped with impurities that introduce extra electrons into the crystal lattice, creating an excess of negative charge. These extra electrons are free to move throughout the material, making them the majority charge carriers. Valence electrons are electrons in the outermost shell of an atom and are not necessarily free to move. Holes are the absence of an electron in the valence band and are considered minority carriers in an n-type semiconductor. Protons are positively charged particles and are not carriers in a semiconductor.Rate this question:
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- 33.
What are the minority carriers in an n-type semiconductors?
- A.
Free electrons
- B.
Valence electrons
- C.
Holes
- D.
Protons
Correct Answer
C. HolesExplanation
In an n-type semiconductor, the majority carriers are free electrons, which are generated due to the presence of impurity atoms with extra valence electrons. However, the minority carriers are holes. Holes are essentially the absence of an electron in the valence band, and they behave as positively charged particles. These holes can move through the crystal lattice, contributing to the conductivity of the material.Rate this question:
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- 34.
What are majority carriers in a p-type semiconductor?
- A.
Free electron
- B.
Valence electrons
- C.
Holes
- D.
Protons
Correct Answer
C. HolesExplanation
In a p-type semiconductor, majority carriers are holes. A p-type semiconductor is created by adding impurities with fewer valence electrons than the host material, creating holes in the crystal lattice. These holes act as positive charge carriers, effectively moving through the material in the opposite direction to the movement of electrons. Therefore, holes are the majority carriers in a p-type semiconductor.Rate this question:
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- 35.
What are the minority carriers in a p-type semiconductor?
- A.
Free electrons
- B.
Valence electrons
- C.
Holes
- D.
Protons
Correct Answer
A. Free electronsExplanation
In a p-type semiconductor, the majority carriers are holes, which are essentially the absence of electrons in the valence band. Minority carriers, on the other hand, are the opposite charge carriers to the majority carriers. Since the majority carriers in a p-type semiconductor are holes (positive charge), the minority carriers would be free electrons (negative charge). These free electrons are present in small numbers and are generated due to thermal excitation or impurity doping.Rate this question:
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- 36.
What is formed when part of a material is doped n-type and part of it is doped p-type?
- A.
Pn junction
- B.
Extrinsic material
- C.
Intrinsic material
- D.
Diode
Correct Answer
A. Pn junctionExplanation
When part of a material is doped n-type and part of it is doped p-type, a pn junction is formed. In a pn junction, the n-type region has an excess of electrons while the p-type region has an excess of holes. This creates a depletion region at the junction where the electrons and holes combine, resulting in a barrier to current flow. The pn junction is the basic building block of various electronic devices, such as diodes, transistors, and solar cells.Rate this question:
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- 37.
A depletion region forms starting at the junction that is devoid of any majority carriers. The depletion region is formed by ___________.
- A.
Thermal conduction
- B.
Doping
- C.
Recombination
- D.
Ionization
Correct Answer
C. RecombinationExplanation
The correct answer is recombination. A depletion region forms at the junction of a semiconductor device when there is a lack of majority carriers. This occurs through a process called recombination, where electrons from the n-type region and holes from the p-type region combine and neutralize each other, creating the depletion region. This region is devoid of any majority carriers, leading to a barrier to the flow of current in the device.Rate this question:
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- 38.
There is current through the pn junction only when it is ____________.
- A.
Reverse-biased
- B.
Unbiased
- C.
Forward-biased
- D.
Open
Correct Answer
C. Forward-biasedExplanation
When a pn junction is forward-biased, the positive terminal of the battery is connected to the p-region and the negative terminal is connected to the n-region. This creates an electric field that allows the majority charge carriers (electrons in the n-region and holes in the p-region) to move across the junction and combine, resulting in current flow. In contrast, when the junction is reverse-biased, the positive terminal is connected to the n-region and the negative terminal is connected to the p-region, which creates a barrier that prevents the majority carriers from crossing the junction, thus no current flows.Rate this question:
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- 39.
Avalance occurs in a reverse-biased pn-junction if the bias voltage _______________ the breakdown voltage.
- A.
Less than
- B.
Greater than
- C.
Equal to
- D.
Choices b or c
Correct Answer
D. Choices b or cExplanation
Avalanche occurs in a reverse-biased pn-junction if the bias voltage is greater than or equal to the breakdown voltage.Rate this question:
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- 40.
Semiconductors are usually materials which have energy-band gaps smaller than _________ eV.
- A.
1
- B.
2
- C.
3
- D.
0.5
Correct Answer
C. 3Explanation
Semiconductors are materials that have energy-band gaps smaller than 3 eV. The energy-band gap refers to the energy difference between the valence band and the conduction band in a material. In semiconductors, this gap is smaller compared to insulators and larger compared to conductors. This characteristic allows semiconductors to conduct electricity under certain conditions, making them ideal for applications in electronics and technology.Rate this question:
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- 41.
Semiconductors have electrical resistivities between____________ and ____________ ohm-meter.
- A.
10^-5, 10^7
- B.
10^-6, 10^6
- C.
10^-5, 10^9
- D.
10^-5, 10^5
Correct Answer
D. 10^-5, 10^5Explanation
Semiconductors have electrical resistivities between 10^-5 and 10^5 ohm-meter. This means that semiconductors have resistivities that are higher than conductors (which typically have resistivities on the order of 10^-8 ohm-meter) but lower than insulators (which typically have resistivities on the order of 10^12 ohm-meter). This range of resistivities allows semiconductors to exhibit unique electrical properties, such as the ability to conduct electricity under certain conditions and act as insulators under others.Rate this question:
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- 42.
Each atom in a silicon crystal has how many valence electrons?
- A.
4
- B.
6
- C.
2
- D.
8
Correct Answer
D. 8Explanation
Each atom in a silicon crystal has 8 valence electrons. Valence electrons are the electrons in the outermost shell of an atom, and they determine the atom's chemical properties and bonding behavior. Silicon, being in Group 14 of the periodic table, has 4 valence electrons in its outermost shell. However, in a crystal structure, each silicon atom forms covalent bonds with four neighboring silicon atoms, resulting in a shared electron arrangement where each atom effectively has 8 valence electrons. This allows silicon to form a stable crystal lattice structure.Rate this question:
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- 43.
What is the atomic number of silicon?
- A.
12
- B.
14
- C.
32
- D.
36
Correct Answer
B. 14Explanation
The atomic number of an element represents the number of protons in the nucleus of its atom. In the case of silicon, the atomic number is 14. This means that a silicon atom has 14 protons in its nucleus.Rate this question:
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- 44.
What is the atomic number of germanium?
- A.
12
- B.
14
- C.
32
- D.
39
Correct Answer
C. 32Explanation
Germanium has an atomic number of 32. The atomic number represents the number of protons in an atom's nucleus. Since germanium has an atomic number of 32, it means that it has 32 protons in its nucleus.Rate this question:
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- 45.
What is the letter designation of the valence shell of a silicon atom?
- A.
K
- B.
L
- C.
M
- D.
N
Correct Answer
C. MExplanation
The letter designation of the valence shell of a silicon atom is M. In the electron configuration of silicon, the valence electrons occupy the third energy level, which is designated as the M shell. The M shell can hold a maximum of 18 electrons.Rate this question:
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- 46.
What refers to the absence of an electron in the valence band?
- A.
Ion
- B.
Hole
- C.
Donor
- D.
Acceptor
Correct Answer
B. HoleExplanation
A hole refers to the absence of an electron in the valence band. In a semiconductor material, when an electron moves from the valence band to the conduction band, it leaves behind a vacant space called a hole. This hole can behave as a positively charged particle and can move through the material in a manner similar to how an electron moves. Holes play a crucial role in the conduction of electricity in semiconductors and are important for understanding the behavior of electronic devices.Rate this question:
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- 47.
What is the energy gap of silicon?
- A.
1.1eV
- B.
0.67eV
- C.
0.87eV
- D.
1.2eV
Correct Answer
A. 1.1eVExplanation
The energy gap of silicon is 1.1eV. The energy gap refers to the energy difference between the valence band and the conduction band in a material. In the case of silicon, this energy gap is 1.1eV, which means that it requires 1.1eV of energy for an electron to move from the valence band to the conduction band and become a free charge carrier. This property of silicon makes it a semiconductor, as it can conduct electricity under certain conditions.Rate this question:
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- 48.
What is the energy gap of germanium?
- A.
1.1eV
- B.
0.67eV
- C.
0.87eV
- D.
1.2eV
Correct Answer
B. 0.67eVExplanation
The energy gap of germanium is 0.67eV. The energy gap refers to the difference in energy between the valence band and the conduction band in a semiconductor. It represents the minimum amount of energy required for an electron to move from the valence band to the conduction band and become a free charge carrier. In the case of germanium, this energy gap is 0.67eV, which means that it requires 0.67eV of energy for an electron to transition from the valence band to the conduction band and contribute to electrical conductivity.Rate this question:
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- 49.
Barrier potential ______________ as temperature increases.
- A.
Remain unchanged
- B.
Become zero
- C.
Increases
- D.
Decreases
Correct Answer
D. DecreasesExplanation
As temperature increases, the barrier potential in a semiconductor decreases. This is because at higher temperatures, more thermal energy is available to free electrons and create electron-hole pairs. These additional charge carriers reduce the effectiveness of the barrier potential in preventing current flow, leading to a decrease in the barrier potential.Rate this question:
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- 50.
What refers to the rapid multiplication of current carriers in reverse breakdown?
- A.
Avalanche
- B.
Bias
- C.
Dynamic
- D.
Barrier potential
Correct Answer
A. AvalancheExplanation
Avalanche refers to the rapid multiplication of current carriers in reverse breakdown. In reverse breakdown, the voltage across a diode increases beyond its breakdown voltage, causing a sudden increase in the number of charge carriers. This multiplication process is known as avalanche, where the charge carriers collide with other atoms and release more charge carriers in the process. This rapid multiplication results in a significant increase in current flow through the diode.Rate this question:
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Current Version
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Mar 19, 2023Quiz Edited by
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Nov 17, 2011Quiz Created by
Toinkxz77
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