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Does the value of thermal conductivity depend on the dimension of the specimen?
Wiki User
∙ 9y ago
Thermal conductivity is an intensive property. It is inherent in the material but not dependent on the amount of material. This should not be confused with the rate of heat conduction which can depend on the dimensions of a material.
There is one case where the thermal conductivity might depend on the dimension of the material - when the conductivity is not uniform with direction, i.e. where conductivity laterally is different from conductivity longitudinally. When the orientation of the material changes the conductivity, the dimensions can have an effect on the apparent bulk thermal conductivity.
Wiki User
∙ 12y ago
Wiki User
∙ 9y agoThermal conductivity is a quality of the material with which the specimen is made. But amount of heat conducted depends on the dimensions of the specimen
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What are the uses of thermal conductivity?
Thermal conductivity is an intrinsic material property for which the values depend on the chemical composition, porosity, density, structure, and fabric of the material . In marine geophysics, mainly thermal conductivity profiles of sediment and rock sections are used, along with temperature measurements, to determine heat flow. Heat flow is not only characteristic of the material, but an indicator of type and age of ocean crust and fluid circulation processes at shallow and great depths.
What three things does thermal energy depend on?
sex, oral, thermal. <3
Difference between electrical conductors and electrical insulators?
QuestionIs there a relationship between electrical conductivity and thermal conductivity?Asked by: Darell HayesAnswerThere is a relationship for metals and it is known as the Wiedemann-Franz law. Metals are good electrical conductors because there are lots of free charges in them. The free charges are usually negative electrons, but in some metals, e.g., tungsten, they are positive 'holes.' For purposes of discussion, let's assume we have free electron charges.When a voltage difference exists between two points in a metal, it creates an electric field which causes the electrons to move, i.e., it causes a current. Of course, the electrons bump into some of the stationary atoms (actually, 'ion cores') of the metal and this frictional 'resistance' tends to slow them down. The resistance depends on the specific type of metal we're dealing with. E.g., the friction in silver is much less than it is in iron. The greater the distance an electron can travel without bumping into an ion core, the smaller is the resistance, i.e., the greater is the electrical conductivity. The average distance an electron can travel without colliding is called the 'mean free path.' But there's another factor at work too. The electrons which are free to respond to the electric field have a thermal speed a sizable percentage of the speed of light, but since they travel randomly with this high speed, they go nowhere on average, i.e., this thermal speed itself doesn't create any current.The thermal conductivity of this metal is, like electrical conductivity, determined largely by the free electrons. Suppose now that the metal has different temperatures at its ends. The electrons are moving slightly faster at the hot end and slower at the cool end. The faster electrons transmit energy to the cooler, slower ones by colliding with them, and just as for electrical conductivity, the longer the mean free path, the faster the energy can be transmitted, i.e., the greater the thermal conductivity. But the rate is also determined by the very high thermal speed-the higher the speed, the more rapidly does heat energy flow(i.e., the more rapidly collisions occur). In fact, the thermal conductivity is directly proportional to the product of the mean free path and thermal speed.Both thermal and electrical conductivity depend in the same way on not just the mean free path, but also on other properties such as electron mass and even the number of free electrons per unit volume. But as we have seen, they depend differently on the thermal speed of the electrons-electrical conductivity is inversely proportional to it and thermal conductivity is directly proportional to it. The upshot is that the ratio of thermal to electrical conductivity depends primarily on the square of the thermal speed. But this square is proportional to the temperature, with the result that the ratio depends on temperature, T, and two physical constants: Boltzmann's constant, k, and the electron charge, e. Boltzmann's constant is, in this context, a measure of how much kinetic energy an electron has per degree of temperature.Putting it all together, the ratio of thermal to electrical conductivity is:( 2 / 3 ) * ( (k/e)2 ) * Tthe value of the constant multiplying T being: 2.45x10-8 W-ohm-K-squared.http://www.physlink.com/education/AskExperts/ae432.cfm
Is tin a good conductor of heat?
Tin is a decent conductor of heat. It has a thermal conductivity constant (k) of 66.8  W·m−1·K−1. Comparably, Aluminum and Copper are good heat conductors with a thermal conductivity of 237 W·m−1·K−1 and 386 W·m−1·K−1, while rubber is a poor conductor with 0.16 W·m−1·K−1.
How does the increase in thermal energy of the cylinder relate to the mass of the falling object?
Thermal energy is generated by the friction with the air (air resistance), it does not depend on the mass but the surface area of a falling object.
What are the uses of thermal conductivity?
Thermal conductivity is an intrinsic material property for which the values depend on the chemical composition, porosity, density, structure, and fabric of the material . In marine geophysics, mainly thermal conductivity profiles of sediment and rock sections are used, along with temperature measurements, to determine heat flow. Heat flow is not only characteristic of the material, but an indicator of type and age of ocean crust and fluid circulation processes at shallow and great depths.
On what does conductivity in a metallic wire depend?
Free electrons only
What three things does thermal energy depend on?
sex, oral, thermal. <3
What would you use to measure a movie ticket?
The answer will depend on whether you want to measure its size, mass, reflectivity, colour, thermal or electric conductivity, etc. And since you have not bothered to provide that crucial bit of information, I cannot provide a more useful answer.
Does thermal energy depend on the amount of a substance?
Thermal energy is heat. More heat is more thermal energy.
Difference between electrical conductors and electrical insulators?
QuestionIs there a relationship between electrical conductivity and thermal conductivity?Asked by: Darell HayesAnswerThere is a relationship for metals and it is known as the Wiedemann-Franz law. Metals are good electrical conductors because there are lots of free charges in them. The free charges are usually negative electrons, but in some metals, e.g., tungsten, they are positive 'holes.' For purposes of discussion, let's assume we have free electron charges.When a voltage difference exists between two points in a metal, it creates an electric field which causes the electrons to move, i.e., it causes a current. Of course, the electrons bump into some of the stationary atoms (actually, 'ion cores') of the metal and this frictional 'resistance' tends to slow them down. The resistance depends on the specific type of metal we're dealing with. E.g., the friction in silver is much less than it is in iron. The greater the distance an electron can travel without bumping into an ion core, the smaller is the resistance, i.e., the greater is the electrical conductivity. The average distance an electron can travel without colliding is called the 'mean free path.' But there's another factor at work too. The electrons which are free to respond to the electric field have a thermal speed a sizable percentage of the speed of light, but since they travel randomly with this high speed, they go nowhere on average, i.e., this thermal speed itself doesn't create any current.The thermal conductivity of this metal is, like electrical conductivity, determined largely by the free electrons. Suppose now that the metal has different temperatures at its ends. The electrons are moving slightly faster at the hot end and slower at the cool end. The faster electrons transmit energy to the cooler, slower ones by colliding with them, and just as for electrical conductivity, the longer the mean free path, the faster the energy can be transmitted, i.e., the greater the thermal conductivity. But the rate is also determined by the very high thermal speed-the higher the speed, the more rapidly does heat energy flow(i.e., the more rapidly collisions occur). In fact, the thermal conductivity is directly proportional to the product of the mean free path and thermal speed.Both thermal and electrical conductivity depend in the same way on not just the mean free path, but also on other properties such as electron mass and even the number of free electrons per unit volume. But as we have seen, they depend differently on the thermal speed of the electrons-electrical conductivity is inversely proportional to it and thermal conductivity is directly proportional to it. The upshot is that the ratio of thermal to electrical conductivity depends primarily on the square of the thermal speed. But this square is proportional to the temperature, with the result that the ratio depends on temperature, T, and two physical constants: Boltzmann's constant, k, and the electron charge, e. Boltzmann's constant is, in this context, a measure of how much kinetic energy an electron has per degree of temperature.Putting it all together, the ratio of thermal to electrical conductivity is:( 2 / 3 ) * ( (k/e)2 ) * Tthe value of the constant multiplying T being: 2.45x10-8 W-ohm-K-squared.http://www.physlink.com/education/AskExperts/ae432.cfm
What is the factorial difference of the special dimension in this universe and one more of the smallest perfect number?
The answer will depend on what dimension[s] you consider to be special.
What does electrical conductivity of a substance depend on?
how much free charged ions there are in a solution
How do you find the dimension of a shape?
The answer will depend on the shape itself and what other information you have about it. Otherwise, there is no option but to measure them.
What is a renewable energy resources that does not depend on the sun?
Wind, wave or geo-thermal
Many of the macroscopic properties of a compound depend on?
Many of the macroscopic properties of a compound depend on the way in which the atoms of the molecules are held together. One macroscopic property is electric conductivity.
Type of thermodynamic properties?
Thermodynamic properties are specific volume, density, pressure, and temperature. Other properties are constant pressure, constant volume specific heats, Gibbs free energy, specific internal energy and enthalpy, and entropy.
