Materials are classified as conductors, insulators, or semiconductors according to their electric conductivity. The classifications can be understood in atomic terms. Electrons in an atom can have only certain well-defined energies, and, depending on their energies, the electrons are said to occupy particular energy levels. In a typical atom with many electrons, the lower energy levels are filled, each with the number of electrons allowed by a quantum mechanical rule known as the Pauli exclusion principle. Depending on the element, the highest energy level to have electrons may or may not be completely full. If two atoms of some element are brought close enough together so that they interact, the two-atom system has two closely spaced levels for each level of the single atom. If 10 atoms interact, the 10-atom system will have a cluster of 10 levels corresponding to each single level of an individual atom. In a solid, the number of atoms and hence the number of levels is extremely large; most of the higher energy levels overlap in a continuous fashion except for certain energies in which there are no levels at all. Energy regions with levels are called energy bands, and regions that have no levels are referred to as band gaps.
Conductors
Conductors are the materials or substances which allow electricity to flow through them. They are able to conduct electricity because they allow electrons to flow inside them very easily. Conductors have this property of allowing the transition of heat or Light from one source to another. Metals, humans, earth, and animal bodies are all conductors. This is the reason we get electric shocks! The main reason is that being a good conductor, our human body allows a resistance-free path for the current to flow from wire to our body. Conductors have free electrons on its surface which allows current to pass through. This is the reason why conductors are able to conduct electricity.
Examples of Conductors
Silver is the best conductor of electricity. However, it is costly and so, we don’t use silver in industries and transmission of electricity.
Copper, Brass, Steel, Gold, and Aluminium are good conductors of electricity. We use them mostly in electric circuits and systems in form of wires.
Mercury is an excellent liquid conductor that finds use in many instruments.
Gases are not good conductors of electricity as the particles of matter are quite far away and thus, they are unable to conduct electrons.
Semiconductors
Semiconductor, any of a class of crystalline solids intermediate in electrical conductivity between a conductor and an insulator. Semiconductors are employed in the manufacture of various kinds of electronic devices, including diodes, transistors, and integrated circuits. Such devices have found wide application because of their compactness, reliability, power efficiency, and low cost. As discrete components, they have found use in power devices, optical sensors, and light emitters, including solid-state lasers. They have a wide range of current- and voltage-handling capabilities and, more important, lend themselves to integration into complex but readily manufacturable microelectronic circuits. They are, and will be in the foreseeable future, the key Elements for the majority of electronic systems, serving communications, signal processing, computing, and control applications in both the consumer and industrial markets.
Solid-state materials are commonly grouped into three classes: insulators, semiconductors, and conductors. (At low temperatures some conductors, semiconductors, and insulators may become superconductors.) The figure shows the conductivities σ (and the corresponding resistivities ρ = 1/σ) that are associated with some important materials in each of the three classes. Insulators, such as fused quartz and glass, have very low conductivities, on the order of 10−18 to 10−10 siemens per centimetre; and conductors, such as aluminum, have high conductivities, typically from 104 to 106 siemens per centimetre. The conductivities of semiconductors are between these extremes and are generally sensitive to temperature, illumination, magnetic fields, and minute amounts of impurity atoms. For example, the addition of about 10 atoms of boron (known as a dopant) per million atoms of silicon can increase its electrical conductivity a thousand fold.
The study of semiconductor materials began in the early 19th century. The elemental semiconductors are those composed of single species of atoms, such as silicon (Si), germanium (Ge), and tin (Sn) in column IV and selenium (Se) and tellurium (Te) in column VI of the periodic table. There are, however, numerous compound semiconductors, which are composed of two or more elements. Gallium arsenide (GaAs), for example, is a binary III-V compound, which is a combination of gallium (Ga) from column III and arsenic (As) from column V. Ternary compounds can be formed by elements from three different columns—for instance, mercury indium telluride (HgIn2Te4), a II-III-VI compound. They also can be formed by elements from two columns, such as aluminum gallium arsenide (AlxGa1 − xAs), which is a ternary III-V compound, where both Al and Ga are from column III and the subscript x is related to the composition of the two elements from 100 percent Al (x = 1) to 100 percent Ga (x = 0). Pure silicon is the most important material for integrated circuit applications, and III-V binary and ternary compounds are most significant for light emission.
Insulators
Insulators are the materials or substances which resist or don’t allow the current to flow through them. They are mostly solid in nature and are finding use in a variety of systems. They do not allow the flow of heat as well. The property which makes insulators different from conductors is its resistivity. Wood, cloth, glass, mica, and quartz are some good examples of insulators. Insulators are also protectors as they give protection against heat, Sound and of course passage of electricity. Insulators don’t have any free electrons and it is the main reason why they don’t conduct electricity.
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Conductors are materials that allow electricity or heat to flow through them easily. They are often used in electrical wiring and appliances.
There are many different types of conductors, including metals, semiconductors, and superconductors. Metals are the best conductors of electricity, followed by semiconductors and then superconductors.
Electrical conductors are materials that allow electricity to flow through them easily. They are often used in electrical wiring and appliances. Some common examples of electrical conductors include copper, aluminum, and silver.
Thermal conductors are materials that allow heat to flow through them easily. They are often used in cooking utensils and heat sinks. Some common examples of thermal conductors include copper, aluminum, and silver.
Sound conductors are materials that allow sound to travel through them easily. They are often used in Musical instruments and loudspeakers. Some common examples of sound conductors include wood, Metal, and glass.
Electromagnetic conductors are materials that allow waves/”>Electromagnetic Waves to travel through them easily. They are often used in radio and television antennas. Some common examples of electromagnetic conductors include copper, aluminum, and silver.
Electrically conductive polymers are polymers that have been modified to conduct electricity. They are often used in batteries and solar cells. Some common examples of electrically conductive polymers include polyacetylene, polypyrrole, and polyaniline.
Superconductors are materials that conduct electricity with zero resistance. They are often used in MRI machines and particle accelerators. Some common examples of superconductors include niobium-titanium, yttrium barium copper oxide, and lanthanum barium copper oxide.
Superfluid conductors are materials that conduct heat with zero resistance. They are often used in research on quantum mechanics. Some common examples of superfluid conductors include helium-3 and helium-4.
Metallic conductors are materials that are made up of atoms that have free electrons. These free electrons can move easily through the material, allowing electricity to flow. Some common examples of metallic conductors include copper, aluminum, and silver.
Semiconductor conductors are materials that have electrical conductivity between that of a conductor and an insulator. They are often used in electronic devices such as transistors and solar cells. Some common examples of semiconductor conductors include silicon and germanium.
Insulators are materials that do not allow electricity or heat to flow through them easily. They are often used in electrical insulation and packaging. Some common examples of insulators include plastic, rubber, and glass.
Dielectrics are materials that are good insulators of electricity. They are often used in capacitors and other electrical components. Some common examples of dielectrics include paper, plastic, and glass.
Semiconductors and insulators are both types of materials that are not good conductors of electricity. However, semiconductors have a higher electrical conductivity than insulators. This is because semiconductors have a small number of free electrons, while insulators have no free electrons.
The electrical conductivity of a material can be affected by a number of factors, including temperature, pressure, and the presence of impurities. For example, the electrical conductivity of metals increases with increasing temperature. This is because the free electrons in metals have more energy at higher temperatures, which allows them to move more easily through the material.
The electrical conductivity of semiconductors also increases with increasing temperature, but to a lesser extent than metals. This is because the number of free electrons in semiconductors increases with increasing temperature.
The electrical conductivity of insulators does not change significantly with temperature. This is because insulators have very few free electrons, and the number of free electrons does not change significantly with temperature.
The electrical conductivity of a material can also be affected by the presence of impurities. For example, the electrical conductivity of metals decreases with the addition of impurities. This is because the impurities can scatter the free electrons, making it more difficult for them to move through the material.
The electrical conductivity of semiconductors increases with the addition of impurities. This is because the impurities can create new energy levels in the material, which can be occupied by free electrons. These free electrons can then move more easily through the material.
The electrical conductivity of insulators is not affected significantly by the presence of impurities. This is because insulators have very few free electrons, and the addition of impurities does not create new energy levels in the material.
What is a conductor?
A conductor is a material that allows electricity to flow through it easily.
What are some examples of conductors?
Some examples of conductors are metals, such as copper, silver, and gold. Other examples include water, salt water, and human body.
What are some uses of conductors?
Conductors are used in a variety of applications, including electrical wiring, batteries, and motors.
What are some properties of conductors?
Conductors have a number of properties that make them useful for electrical applications. These properties include:
High conductivity: Conductors allow electricity to flow through them easily.
Low resistance: Conductors have low resistance to the flow of electricity.
Malleability: Conductors can be easily shaped and formed.
Ductility: Conductors can be drawn into thin wires.
What are some safety precautions to take when working with conductors?
When working with conductors, it is important to take the following safety precautions:
Use insulated tools.
Wear safety glasses.
Be aware of the potential for electrical shock.
What are some common problems with conductors?
Some common problems with conductors include:
Oxidation: Conductors can oxidize over time, which can reduce their conductivity.
Corrosion: Conductors can corrode, which can also reduce their conductivity.
Damage: Conductors can be damaged by physical abuse, such as being bent or cut.
How can conductors be repaired or replaced?
Conductors that are damaged can be repaired or replaced. Repairs can be made by soldering or welding the conductor. Replacements can be made by using a new conductor.
What is the future of conductors?
The future of conductors is likely to be bright. Conductors are used in a variety of applications, and the demand for conductors is expected to grow in the future. New technologies are being developed to improve the performance of conductors, and new materials are being developed to replace traditional conductors.
Which of the following is a good conductor of electricity? (A) Wood (B) Rubber (C) Silver (D) Plastic
Which of the following is a good insulator of electricity? (A) Copper (B) Glass (C) Water (D) Air
What is the name of the force that attracts oppositely charged particles and repels like-charged particles? (A) Gravity (B) Electromagnetism (C) Nuclear force (D) Chemical force
What is the name of the device that measures electric current? (A) Ammeter (B) Voltmeter (C) Ohmmeter (D) Wattmeter
What is the name of the device that measures electric potential difference? (A) Ammeter (B) Voltmeter (C) Ohmmeter (D) Wattmeter
What is the name of the device that measures electric resistance? (A) Ammeter (B) Voltmeter (C) Ohmmeter (D) Wattmeter
What is the name of the device that measures electric power? (A) Ammeter (B) Voltmeter (C) Ohmmeter (D) Wattmeter
What is the name of the unit of electric current? (A) Ampere (B) Volt (C) Ohm (D) Watt
What is the name of the unit of electric potential difference? (A) Ampere (B) Volt (C) Ohm (D) Watt
What is the name of the unit of electric resistance? (A) Ampere (B) Volt (C) Ohm (D) Watt
What is the name of the unit of electric power? (A) Ampere (B) Volt (C) Ohm (D) Watt
What is the formula for electric current? (A) $I = \frac{V}{R}$ (B) $V = IR$ (C) $R = \frac{V}{I}$ (D) $P = VI$
What is the formula for electric potential difference? (A) $I = \frac{V}{R}$ (B) $V = IR$ (C) $R = \frac{V}{I}$ (D) $P = VI$
What is the formula for electric resistance? (A) $I = \frac{V}{R}$ (B) $V = IR$ (C) $R = \frac{V}{I}$ (D) $P = VI$
What is the formula for electric power? (A) $I = \frac{V}{R}$ (B) $V = IR$ (C) $R = \frac{V}{I}$ (D) $P = VI$
What is the name of the law that states that the current through a conductor is directly proportional to the voltage across it, and inversely proportional to the resistance of the conductor? (A) Ohm’s law (B) Kirchhoff’s law (C) Faraday’s law (D) Lenz’s law
What is the name of the law that states that the total current entering a junction must equal the total current leaving the junction? (A) Ohm’s law (B) Kirchhoff’s law (C) Faraday’s law (D) Lenz’s law
What is the name of the law that states that the induced voltage in a circuit is proportional to the rate of change of magnetic flux through the circuit? (A) Ohm’s law (B) Kirchhoff’s law (C) Faraday’s law (D) Lenz’s law
What is the name of the law that states that the induced current in a circuit is in a direction that opposes the change that caused it? (A) Ohm’s law (B) Kirchhoff’s law (C) Faraday’s law (D) Lenz’s law
What is the name of the device that converts electrical energy into mechanical energy? (A) Motor (B) Generator (C) Transformer (D) Inductor