In a _____, the voltage is stepped up on the secondary side which causes the current to drop.
Step Up Transformer
What is the benefit of higher power factor?
Lower operating cost
How are the leads arranged in a wye or star connection?
Three are connected together, and three are brought out to connect to the load
The line currents of a delta-connected generator are _____
Equal in value and 120 degrees apart
Clamp on ammeters measure current by measuring what?
The strength of the flux field around a conductor
What needs to happen in an AC generator before it can produce voltage?
The rotor must be excited
What is a rotor?
The rotating part of an AC generator
Why is three phase power preferred to single phase?
Less copper is required to deliver the same amount of power
When analyzing a parallel inductive-resistive-capacitive circuit, what is assumed?
Each branch is purely inductive, capacitive, or resistive
_____ must be known in order to calculate inductive resistance
Frequency
In a parallel-Inductive-capacitive circuit, the power factor is equal to _____
The true power divided by the apparent power
In a series-inductive-capacitive circuit, inductive and capacitive voltages are not _____
In phase with each other
In a series AC circuit, _____ and _____ are in phase with each other
Source voltage and line current
What is the standard power source line frequency in the United States?
60Hz
What must be known in an inductive AC circuit to find current?
The source voltage
What is CEMF and how is it created?
Counter electomotive force, created by a change in current caused by a constantly changing magnetic field
What is a pure inductive circuit?
An AC circuit with no resistance
What is considered low power factor?
Any power factor less than 90%
What is the difference between true power and reactive power?
True power is supplied to a resistive load to do work
_____ circuits are frequently used in electronics applications
Series/Parallel Resistive-Capacitive circuits
When a circuit is _____, the current lags the source voltage.
Inductive
Increasing the frequency in a parralel inductive-resistive-capacitive circuit causes current flow to decrease in the _____ branch
Inductive
Inductive capacitive branches of a circuit _____ have resistance
Do
Using Ohm’s Law, current is often reduce to _____ in order to calculate total line current.
its vertical and horizontal components
_____ is the opposition to current flow by a capacitor
Capacitive Resistance
When analyzing a series circuit, _____ is used as a reference for all other circuit parameters
Current
_____ is the same across all branch circuits of a parallel inductive-resistive-capacitive circuit
Voltage
Series/parallel inductive-resistive-capacitive circuitsare usually analyzed to calculate _____, _____, _____, but not _____
Power Factor, Circuit Power, Total Circuit Current, Frequency
What is Eddy Current Loss?
Power loss in a transformer or motor due to induced current in surrounding metal structures
What is an Isolation Transformer?
A transformer with equal primary and secondary winding used to separate the source from the load
What is a swamping resistor?
A resistor used to suppress the high inductive kick of an exciter current
Three-phase power system use three individual _____ to transmit power
Conductors
_____ measure current by measuring the strength of the current around a single conductor
Clamp-On Ammeters
A _____ is a test instrument used to measure true power in a circuit
Wattmeter
A _____ is not an example of an inductive load
Motor Under Full Load
What is plugging?
Switching polarities in a motor to brake
Frequency changes only directly effect _____, the rest of the parameters are indirectly affected.
Capacitive Reactance
In a pure capacitive circuit, the current _____ the source voltage by 90 degrees
Leads
In a series-capacitive circuit _____ is the same at all points for all components
Current
What is the common method for correcting power factor?
Connecting capacitors across the load
What is Power Factor?
The ratio of true power to apparent power
True power is measured in _____
Watts