Glossary 355
resistor: An electrical component used to limit
current fl ow and divide voltage. (8)
resistor color code: A system of using color
bands on resistors to indicate resistance
rating and tolerance. (8)
reverse engineering: A method of determining
the properties or function of a device by
taking it apart and looking at its operation
structure. (6)
“right to know” laws: Laws that are designed
to ensure people know what chemicals they
are being exposed to and what the health
effects could be. Employees have a right
to know what chemicals they are using at
work. Community members who live near
plants using hazardous chemicals have
a right to know what chemicals they are
exposed to. (15)
risk analysis: A process that identifi es and
evaluates as many of the potential impacts of
an engineered solution as possible. (16)
roadway: The horizontal structure that enables
transportation across the bridge. (9)
robot: An automatically controlled,
reprogrammable, multipurpose machine. (12)
rotary actuator: A device that can provide a
small amount of rotation. (10)
rotary motion: Motion that moves in a circle. (10)
rough sketch: The fi rst drawings completed by
engineers, of solutions that are in the early
stages of development. (4)
rudder: The control surface located on the rear of
the vertical stabilizer, used to control side-to-
side movement of the nose. (13)
S
sales engineer: An engineer who works with
clients to fi nd products that meet their
needs. (16)
satellite: A type of spacecraft that orbits the
Earth because the centrifugal force created
by its motion is in perfect balance with the
Earth’s gravitational pull. (13)
schematic diagram: A basic sketch of circuitry
showing schematic symbols for parts and
lines to represent conductors. (8)
schematic drawing: A type of working drawing
used to show how different parts are
connected together to form a system. (5)
schematic symbols: Simple symbols used to
represent electrical parts. (8)
screw: A simple machine that is an inclined
plane wrapped around a cylinder. (10)
second law of thermodynamics: The law often
called the entropy law, concerned with the
idea that concentrated sources of energy will
naturally disperse. (15)
secondary cell: A cell that can be recharged. (8)
secondary processing: The processing of stock
materials into useful products. (14)
selecting and sequencing manufacturing
operations: The decisions of what
operations, or processes, will be used to
create the product and in what order, or
sequence, they will be performed. (14)
semiconductor: A material with conductive
capabilities between that of conductors
and insulators. Silicon is the most common
semiconductor. (8)
sensor: A component that creates an electrical
signal based on environmental conditions.
A sensor can be used to monitor things like
temperature and light. (8)
separating: The process of cutting materials
to the desired size or shape through
mechanical, heat, or chemical means. (14)
series circuits: Circuits with only one path
for current to fl ow from the power source
through the circuit and back to the power
source. (8)
series-parallel combination circuits: Circuits
with characteristics of both series and
parallel circuits. (8)
shaft: A cylindrical piece used to transfer rotary
motion. (10)
shape dimension: A type of dimension used
to provide detailed information about the
shape of features. (5)
shear: A force that acts in opposite directions
across a material. (9)
shear stress: A bending or twisting force, like the
stress that occurs when using a wrench. (7)