Chapter 2
... produced. For example, if we put several cups of coffee in the same room, they will all reach the same final temperature, regardless of their different initial temperatures or how much milk was added. However, there are many cases where the history of the system is important. For example, a metal co ...
... produced. For example, if we put several cups of coffee in the same room, they will all reach the same final temperature, regardless of their different initial temperatures or how much milk was added. However, there are many cases where the history of the system is important. For example, a metal co ...
- Pcpolytechnic
... chemical equilibrium when there are no chemical reactions going on within the system or there is no transfer of matter from one part of the system to other due to diffusion. Two systems are said to be in chemical equilibrium with each other when their chemical potentials are same. Thermal equilibriu ...
... chemical equilibrium when there are no chemical reactions going on within the system or there is no transfer of matter from one part of the system to other due to diffusion. Two systems are said to be in chemical equilibrium with each other when their chemical potentials are same. Thermal equilibriu ...
basic thermodynamics
... exempt from the limitations of the second law, while conversion of low grade energy is subjected to them. Example: High grade energy: 1) Mechanical work 2) electrical energy 3) water power 4) wind power 5) kinetic energy of a jet 6) tidal power. Example: Low grade energy: 1) Heat or thermal energy 2 ...
... exempt from the limitations of the second law, while conversion of low grade energy is subjected to them. Example: High grade energy: 1) Mechanical work 2) electrical energy 3) water power 4) wind power 5) kinetic energy of a jet 6) tidal power. Example: Low grade energy: 1) Heat or thermal energy 2 ...
Thermal Ratings of Surface Mount Packages
... drain leads, and a ground plane, the thermal impedance should be 1.0 to 1.2 times the datasheet value and such rules of thumb are usually sufficiently accurate. The effect of transients (defined as anything less than ~100 seconds in this context) can be taken from the transient thermal impedance cur ...
... drain leads, and a ground plane, the thermal impedance should be 1.0 to 1.2 times the datasheet value and such rules of thumb are usually sufficiently accurate. The effect of transients (defined as anything less than ~100 seconds in this context) can be taken from the transient thermal impedance cur ...
Black-body radiation
Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black body (an opaque and non-reflective body) held at constant, uniform temperature. The radiation has a specific spectrum and intensity that depends only on the temperature of the body.The thermal radiation spontaneously emitted by many ordinary objects can be approximated as blackbody radiation. A perfectly insulated enclosure that is in thermal equilibrium internally contains black-body radiation and will emit it through a hole made in its wall, provided the hole is small enough to have negligible effect upon the equilibrium.A black-body at room temperature appears black, as most of the energy it radiates is infra-red and cannot be perceived by the human eye. Because the human eye cannot perceive color at very low light intensities, a black body, viewed in the dark at the lowest just faintly visible temperature, subjectively appears grey (but only because the human eye is sensitive only to black and white at very low intensities - in reality, the frequency of the light in the visible range would still be red, although the intensity would be too low to discern as red), even though its objective physical spectrum peaks in the infrared range. When it becomes a little hotter, it appears dull red. As its temperature increases further it eventually becomes blindingly brilliant blue-white.Although planets and stars are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is used as a first approximation for the energy they emit.Black holes are near-perfect black bodies, in the sense that they absorb all the radiation that falls on them. It has been proposed that they emit black-body radiation (called Hawking radiation), with a temperature that depends on the mass of the black hole.The term black body was introduced by Gustav Kirchhoff in 1860. When used as a compound adjective, the term is typically written as hyphenated, for example, black-body radiation, but sometimes also as one word, as in blackbody radiation. Black-body radiation is also called complete radiation or temperature radiation or thermal radiation.