RELUCTANCE-- A measure of the opposition that
PICO-- A prefix adopted by the National Bureau of
a material offers to magnetic lines of force.
Standards meaning 10-12.
REPULSION-- The mechanical force tending to
P I E Z O E L E C T R I C E F F E C T -- The effect of
separate bodies having like electrical charges or
producing a voltage by placing a stress, either by
like magnetic polarity.
compression, expansion, or twisting, on a crystal
and, conversely, producing a stress in a crystal
RESIDUAL MAGNETISM-- Magnetism remaining
by applying a voltage to it.
in a substance after removal of the magnetizing
force.
POLARITY-- (1) The condition in an electrical
circuit by which the direction of the flow of
RETENTIVITY-- The ability of a material to retain
current can be determined. Usually applied to
its magnetism.
batteries and other dc voltages sources. (2) Two
opposite charges, one positive and one negative.
RHEOSTAT-- (1) A resistor whose value can be
(3) A quality of having two opposite magnetic
varied. (2) A variable resistor that is used for
poles, one north and the other south.
the purpose of adjusting the current in a circuit.
P O L A R I Z A T I O N -- The effect of hydrogen
surrounding the anode of a cell which increases
RLC CIRCUIT-- An electrical circuit that has the
the internal resistance of the cell.
properties of resistance, inductance, and
POTENTIAL ENERGY-- Energy due to the position
of one body with respect to another body or to
RMS-- Abbreviation of root mean square.
the relative parts of the same body.
ROOT MEAN SQUARE (RMS)-- The equivalent
POTENTIOMETER-- A three-terminal resistor with
heating value of an alternating current or
one or more sliding contacts, which functions as
voltage, as compared to a direct current or
an adjustable voltage divider.
voltage. It is 0.707 times the peak value of a
sine wave.
POWER-- The rate of doing work or the rate of
expending energy. The unit of electrical power
ROTARY SWITCH-- A multicontact switch with
is the watt.
contacts arranged in a circular or semicircular
manner.
P R I M A R Y W I N D I N G -- The winding of a
S
transformer connected to the electrical source.
R
SCHEMATIC CIRCUIT DIAGRAM-- A circuit
diagram in which component parts are
RECIPROCAL-- The value obtained by dividing the
represented by simple, easily drawn symbols.
number 1 by any quantity.
May be called a schematic.
SCHEMATIC SYMBOLS-- Letters, abbreviations, or
R E C T I F I E R -- A device used to convert ac to
designs used to represent specific characteristics
pulsating dc.
or components on a schematic diagram.
REFERENCE POINT-- A point in a circuit to which
all other points in the circuit are compared.
SECONDARY-- The output coil of a transformer.
S E L F - I N D U C T I O N -- The production of a
RELAY-- An electromagnetic device, with one or
counter-electromotive force in a conductor when
more sets of contacts, that changes contact
its own magnetic field collapses or expands with
position by the magnetic attraction of a coil to
a change in current in the conductor.
an armature.
AI-6
