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High Definition Television, any television system with more than 625 scan lines. headphone An audio transducer or pair of transducers arranged to be worn on (or in) the ear. heat transfer The study of the flow of heat energy; heat transfer concerns dictate major design features of most electrical and electronic systems. heatsink
Also called chordal or DC resistance This corresponds to the usual definition of resistance; the voltage divided by the current R s t a t i c = V I. {\displaystyle R_{\mathrm {static} }={V \over I}.} It is the slope of the line (chord) from the origin through the point on the curve. Static resistance determines the power dissipation in an electrical component. Points on the current–voltage ...
Electrical conductivity (or specific conductance) is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter σ , but κ (especially in electrical engineering) [citation needed] and γ [citation needed] are sometimes
The siemens (symbol: S) is the unit of electric conductance, electric susceptance, and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is equal to the reciprocal of one ohm (Ω −1) and is also referred to as the mho.
The electrical resistance of a uniform conductor is given in terms of resistivity by: [40] = where ℓ is the length of the conductor in SI units of meters, a is the cross-sectional area (for a round wire a = πr 2 if r is radius) in units of meters squared, and ρ is the resistivity in units of ohm·meters.
The electrical resistance of an object is a measure of its opposition to the flow of electric current. The inverse quantity is electrical conductance, and is the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with the notion of mechanical friction.
One of the functions of many types of multimeters is the measurement of resistance in ohms.. The ohm is defined as an electrical resistance between two points of a conductor when a constant potential difference of one volt (V), applied to these points, produces in the conductor a current of one ampere (A), the conductor not being the seat of any electromotive force.
In electrical networks, a parasitic impedance is a circuit element (resistance, inductance or capacitance) which is not desirable in an electrical component for its intended purpose. For instance, a resistor is designed to possess resistance, but will also possess unwanted parasitic capacitance. Parasitic impedances are unavoidable.