[R]

Rad - the unit of radiation dose which is absorbed, equal to 100 ergs/gram.

Rated Temperature - The maximum temperature at which an electric component can operate for extended periods without loss of its basic properties.

Rated Voltage - The maximum voltage at which an electric component can operate for extended periods without undue degradation or safety hazard.

Reactance - A measure of the combined effects of capacitance and inductance on an alternating current. The amount of such opposition varies with the frequency of the current. The reactance of a capacitor decreases with an increase in frequency; the opposite occurs with an inductance.

Reference Junction - the junction of a thermocouple which is as a known reference temperature. Also known as the "cold" junction,. It is usually located at the emf measuring device.

Reflection Loss - The part of a signal which is lost due to reflection of power at a line discontinuity.

Registration - Alignment of one object with relation to another. In flat cables it involves aligning conductors with contacts or solder pads. Also called register.

Resin - an organic substance of natural or synthetic origin characterized by being polymeric in structure and predominantly amorphous. Most resins, through not all, are of high molecular weight and consist of long chain or network molecular structure.

Resistance - In dc circuits, the opposition a material offers to current flow, measured in ohms. In ac circuits, resistance is the real component of impedance, and may be higher than the value measured at dc.

Retractile Cable - a cable that returns by its own stored energy from an extended condition to it original contracted form.