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What is electrical resistance?
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Electric resistivity is defined as the electrical resistance offered per unit length and unit cross-sectional area at a specific temperature and is denoted by ρ. Electrical resistance is also known as specific electrical resistance.
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Dec 28, 2020 · Learn how resistance is a measure of opposition to electric current and how it affects the flow of electrons. Find out how to calculate resistance, how to use Ohm's law, and how to deal with resistors in series and parallel.
The resistivity is a characteristic of the material used to fabricate a wire or other electrical component, whereas the resistance is a characteristic of the wire or component. To calculate the resistance, consider a section of conducting wire with cross-sectional area A, length L, and resistivity .
Resistance is the property of a material or component that opposes the flow of electric current through it. It is measured in Ohms and denoted by the symbol “Ω”. Resistance arises due to the interactions between electrons and the atoms or molecules that make up the material.
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An electron traveling through the wires and loads of the external circuit encounters resistance. Resistance is the hindrance to the flow of charge. For an electron, the journey from terminal to terminal is not a direct route. Rather, it is a zigzag path that results from countless collisions with fixed atoms within the conducting material. The elec...
The flow of charge through wires is often compared to the flow of water through pipes. The resistance to the flow of charge in an electric circuit is analogous to the frictional effects between water and the pipe surfaces as well as the resistance offered by obstacles that are present in its path. It is this resistance that hinders the water flow a...
A third variable that is known to affect the resistance to charge flow is the material that a wire is made of. Not all materials are created equal in terms of their conductive ability. Some materials are better conductors than others and offer less resistance to the flow of charge. Silver is one of the best conductors but is never used in wires of ...
As seen in the table, there is a broad range of resistivity values for various materials. Those materials with lower resistivities offer less resistance to the flow of charge; they are better conductors. The materials shown in the last four rows of the above table have such high resistivity that they would not even be considered to be conductors.
Resistance is a numerical quantity that can be measured and expressed mathematically. The standard metric unit for resistance is the ohm, represented by the Greek letter omega - . An electrical device having a resistance of 5 ohms would be represented as R = 5 . The equation representing the dependency of the resistance (R) of a cylindrically shape...
1. Household circuits are often wired with two different widths of wires: 12-gauge and 14-gauge. The 12-gauge wire has a diameter of 1/12 inch while the 14-gauge wire has a diameter of 1/14 inch. Thus, 12-gauge wire has a wider cross section than 14-gauge wire. A 20-Amp circuit used for wall receptacles should be wired using 12-gauge wire and a 15-...
2. Based on the information stated in the above question, explain the risk involved in using 14-gauge wire in a circuit that will be used to power an 16-ampere power saw.
4. Two wires - A and B - with circular cross-sections have identical lengths and are made of the same material. Yet, wire A has four times the resistance of wire B. How many times greater is the diameter of wire B than wire A?
Learn what resistance is, how it affects the flow of charge, and how it depends on variables such as length, area, and material. Explore the mathematical formula, resistivity table, and examples of resistors.
Learn about resistance, a property of materials that limits the flow of current, and Ohm's law, which relates voltage, current and resistance. Explore the concepts of superconductivity, a phenomenon of zero resistance and expulsion of magnetic fields in certain materials.
Having more lamps in series means that the resistance of the circuit is more. Less current flows so the bulbs are dimmer. Resistance is measured in units called ohms, which is...
