f.
Potential difference The potential difference (p.
Plastic plugs plastic plug made hollow plastic tube split half its length to
allow for expansion.
Risk risk the ‘likelihood’ harm actually being done. the regulation to
be met ‘so far reasonably practicable’, then risks, cost, time, trouble
and difficulty can considered. Each size plastic plug colour-coded match a
wood screw size.
Polyvinylchloride (PVC) PVC used for cable insulation thermoplastic polymer.d.) defined the cosine the phase angle between the
current and voltage.
Rubber Rubber tough elastic substance made from the sap tropical plants.
Resistance any circuit, resistance defined opposition current flow.
. This also called the volt drop terminal volt-
age, since emf and p.Glossary terms
381
Personal protective equipment PPE defined all equipment designed worn, held, protect
(PPE) against risk health and safety. Once the active chemicals are
exhausted, the cell must discarded.d.
Phasor phasor straight line, having definite length and direction, which rep-
resents scale the magnitude and direction quantity such cur-
rent, voltage impedance.
Protective equipotential bonding This equipotential bonding for the purpose safety. are both measured volts.
Power Power the rate doing work.
Reasonably practicable absolute the requirement the regulation absolute, then that regulation must
be met regardless cost any other consideration.
Power
Work done
Time taken
W
)
Pressure stress Pressure stress measure the force per unit area.
Risk assessments Risk assessments need suitable and sufficient, not perfect.
Pressure stress
Force
Area
N/m
)
2
Primary cell primary cell cannot recharged.
Relay relay electromagnetic switch operated solenoid.) the change energy levels measured
across the load terminals.
PVC/SWA cable installations Steel wire armoured PVC insulated cables are now extensively used on
industrial installations and often laid cable tray.
Power factor Power factor (p.
Resistivity The resistivity (symbol the Greek letter ‘rho’) material defined as
the resistance sample unit length and unit cross-section
