RCDD/TDMM Chapter 9) Power
Distribution questions n answers
rated A+
Authority having jurisdiction - correct answer ✔✔AHJ
A current flow that alternates periodically (usually sinusoidal) in magnitude and direction -
correct answer ✔✔Alternate Current (ac)
The product of the measured voltage and measured amperage. Expressed in volt amperes -
correct answer ✔✔Apparent Power
A short circuit through the air. When insulation and isolation between electrified conductors is
breached or can no longer withstand the applied voltage, an arc flash occurs - correct answer
✔✔Arc Flash
American Wire Gauge; the greater the wire diameter, the smaller the AWG value - correct
answer ✔✔AWG
1) The ability of an electronic component to store electrical energy 2) The opposition to a
change in voltage - correct answer ✔✔Capacitance
The difference between two values, symbolized with a triangle - correct answer ✔✔Delta
Current flow that has a constant direction. The letters dc are also used to generically refer to any
constant waveform or signal. (EG; a batter voltage of 3 volts direct current [3Vdc]) - correct
answer ✔✔Direct Current (dc)
,The number of cycles that a periodic signal completes in a given time. If the unit of time is one
second, the frequency is stated in hertz (Hz). One Hz is equal to one cycle per second - correct
answer ✔✔Frequency
Multiples of the basic frequency of a sine wave (eg the 3rd harmonic of 60 Hz power frequency
is 180 Hz) - correct answer ✔✔Harmonics
The total opposition to ac flow, measured in ohms. - correct answer ✔✔Impedance
1) The property of an electric force field built around a conductor when current flows through it.
2) The resistance to change in current - correct answer ✔✔Inductance
Information Technology Equipment Power; the power consumed by ICT to manage, monitor,
control, process, store, and route data within a data center, excluding all infrastructure
technology equipment - correct answer ✔✔ITE Power
Lockout/ Tagout, a means to protect personnel from the unexpected startup or re-energization
of equipment by ensuring that equipment remains completely off during routing maintenance
and repairs. - correct answer ✔✔LOTO
Low voltage disconnect; a device that is used to disconnect the battery at a preset voltage
during battery discharge and allow reconnection only when utility power has been restored.
Called a 'no volt release' in the UK - correct answer ✔✔LVD
Unwanted electrical signals that were induced onto or superimposed upon the power line -
correct answer ✔✔Noise
Power distribution unit; a device that has a transformer, surge suppression, single point ground,
panelboards, and monitoring under a single enclosure - correct answer ✔✔PDU
, The relationship in time between two waveforms with the same frequency - correct answer
✔✔Phase difference
The number of phases and the type of connection between the utility and the user - correct
answer ✔✔Phase configuration
1) The rate of transfer or absorption of energy per unit time into a system 2) The energy
required to operate an electrical device (EG: Motor, amplifier, transmitter) - correct answer
✔✔Power
The opposition to the flow of ac current caused by unductance and capacitance. Expressed in
ohms. - correct answer ✔✔Reactance
Providing secondary components that either become instantly operational or are continuously
operational so that the failure of a primary component will not result in mission failure - correct
answer ✔✔Redundancy
A measure of opposition a material offers to the flow of direct current. Measured in ohms. -
correct answer ✔✔Resistance
Remote Power Panel; a power distribution cabinet downstream from a PDU or UPS, typically
containing circuits or breakers, without a transformer located near the load. - correct answer
✔✔RPP
Safety Data Sheet; a document prepared by the manufacturer describing all known chemical,
radiological, and other hazards of a specific product. Formerly called a material safety data
sheet (MSDS) - correct answer ✔✔SDS
Distribution questions n answers
rated A+
Authority having jurisdiction - correct answer ✔✔AHJ
A current flow that alternates periodically (usually sinusoidal) in magnitude and direction -
correct answer ✔✔Alternate Current (ac)
The product of the measured voltage and measured amperage. Expressed in volt amperes -
correct answer ✔✔Apparent Power
A short circuit through the air. When insulation and isolation between electrified conductors is
breached or can no longer withstand the applied voltage, an arc flash occurs - correct answer
✔✔Arc Flash
American Wire Gauge; the greater the wire diameter, the smaller the AWG value - correct
answer ✔✔AWG
1) The ability of an electronic component to store electrical energy 2) The opposition to a
change in voltage - correct answer ✔✔Capacitance
The difference between two values, symbolized with a triangle - correct answer ✔✔Delta
Current flow that has a constant direction. The letters dc are also used to generically refer to any
constant waveform or signal. (EG; a batter voltage of 3 volts direct current [3Vdc]) - correct
answer ✔✔Direct Current (dc)
,The number of cycles that a periodic signal completes in a given time. If the unit of time is one
second, the frequency is stated in hertz (Hz). One Hz is equal to one cycle per second - correct
answer ✔✔Frequency
Multiples of the basic frequency of a sine wave (eg the 3rd harmonic of 60 Hz power frequency
is 180 Hz) - correct answer ✔✔Harmonics
The total opposition to ac flow, measured in ohms. - correct answer ✔✔Impedance
1) The property of an electric force field built around a conductor when current flows through it.
2) The resistance to change in current - correct answer ✔✔Inductance
Information Technology Equipment Power; the power consumed by ICT to manage, monitor,
control, process, store, and route data within a data center, excluding all infrastructure
technology equipment - correct answer ✔✔ITE Power
Lockout/ Tagout, a means to protect personnel from the unexpected startup or re-energization
of equipment by ensuring that equipment remains completely off during routing maintenance
and repairs. - correct answer ✔✔LOTO
Low voltage disconnect; a device that is used to disconnect the battery at a preset voltage
during battery discharge and allow reconnection only when utility power has been restored.
Called a 'no volt release' in the UK - correct answer ✔✔LVD
Unwanted electrical signals that were induced onto or superimposed upon the power line -
correct answer ✔✔Noise
Power distribution unit; a device that has a transformer, surge suppression, single point ground,
panelboards, and monitoring under a single enclosure - correct answer ✔✔PDU
, The relationship in time between two waveforms with the same frequency - correct answer
✔✔Phase difference
The number of phases and the type of connection between the utility and the user - correct
answer ✔✔Phase configuration
1) The rate of transfer or absorption of energy per unit time into a system 2) The energy
required to operate an electrical device (EG: Motor, amplifier, transmitter) - correct answer
✔✔Power
The opposition to the flow of ac current caused by unductance and capacitance. Expressed in
ohms. - correct answer ✔✔Reactance
Providing secondary components that either become instantly operational or are continuously
operational so that the failure of a primary component will not result in mission failure - correct
answer ✔✔Redundancy
A measure of opposition a material offers to the flow of direct current. Measured in ohms. -
correct answer ✔✔Resistance
Remote Power Panel; a power distribution cabinet downstream from a PDU or UPS, typically
containing circuits or breakers, without a transformer located near the load. - correct answer
✔✔RPP
Safety Data Sheet; a document prepared by the manufacturer describing all known chemical,
radiological, and other hazards of a specific product. Formerly called a material safety data
sheet (MSDS) - correct answer ✔✔SDS
