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  2. Antimagnetic watch - Wikipedia

    en.wikipedia.org/wiki/Antimagnetic_watch

    According to ISO 764 or its equivalent DIN 8309 (Deutsches Institut für Normung - German Institute for Standardization) a watch must resist exposure to a direct current magnetic field of 4800 A/m. The watch must keep its accuracy to ±30 seconds/day as measured before the test in order to be acknowledged as a magnetic-resistant watch.

  3. Poynting vector - Wikipedia

    en.wikipedia.org/wiki/Poynting_vector

    In physics, the Poynting vector (or Umov–Poynting vector) represents the directional energy flux (the energy transfer per unit area, per unit time) or power flow of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m 2 ); kg/s 3 in SI base units .

  4. Four-current - Wikipedia

    en.wikipedia.org/wiki/Four-current

    is the charge density measured by an inertial observer O who sees the electric current moving at speed u (the magnitude of the 3-velocity); ρ 0 {\displaystyle \rho _{0}} is “the rest charge density”, i.e., the charge density for a comoving observer (an observer moving at the speed u - with respect to the inertial observer O - along with ...

  5. Maximum power transfer theorem - Wikipedia

    en.wikipedia.org/wiki/Maximum_power_transfer_theorem

    Simplified model for powering a load with resistance R L by a source with voltage V S and resistance R S.. The theorem was originally misunderstood (notably by Joule [4]) to imply that a system consisting of an electric motor driven by a battery could not be more than 50% efficient, since the power dissipated as heat in the battery would always be equal to the power delivered to the motor when ...

  6. Pseudo-range multilateration - Wikipedia

    en.wikipedia.org/wiki/Pseudo-range_multilateration

    Pseudo-range multilateration, often simply multilateration (MLAT) when in context, is a technique for determining the position of an unknown point, such as a vehicle, based on measurement of biased times of flight (TOFs) of energy waves traveling between the vehicle and multiple stations at known locations.

  7. Gauss (unit) - Wikipedia

    en.wikipedia.org/wiki/Gauss_(unit)

    The gauss is the unit of magnetic flux density B in the system of Gaussian units and is equal to Mx/cm 2 or g/Bi/s 2, while the oersted is the unit of H-field. One tesla (T) corresponds to 10 4 gauss, and one ampere (A) per metre corresponds to 4π × 10 −3 oersted.

  8. Plasma parameters - Wikipedia

    en.wikipedia.org/wiki/Plasma_parameters

    The plasma collisionality is defined as [4] [5] =, where denotes the electron-ion collision frequency, is the major radius of the plasma, is the inverse aspect-ratio, and is the safety factor. The plasma parameters m i {\displaystyle m_{\mathrm {i} }} and T i {\displaystyle T_{\mathrm {i} }} denote, respectively, the mass and temperature of the ...

  9. Power transmission - Wikipedia

    en.wikipedia.org/wiki/Power_transmission

    A surviving example from 1780 exists at Bad Kösen that transmits power approximately 200 meters from a waterwheel to a salt well, and from there, an additional 150 meters to a brine evaporator. [2] This technology survived into the 21st century in a handful of oilfields in the US, transmitting power from a central pumping engine to the ...