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IEC year 2 part 3 Questions and Answers Fully Solved
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Exam of 31 pages for the course IEC at IEC (IEC year 2 part 3)
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IEC year 2 part 3___ law states "charged bodies attract or repel each other with a force that is directly
proportional to the product of the charges and inversely proportional to the square of the
distance between them." - answer Coulomb’s
Which of the formulas, shown below, is correct to find the equivalent of three inductors
in a parallel circuit? - answerLT= 1 / ( 1/L1 + 1/L2 + 1/L3)
If the RMS value is 125 volts, what is the peak value? - answer176.75
Which of the symbols, shown below, is used to represent an inductor in a schematic
circuit? - answer219 RW Q4 C
Electrical current is the flow of ___. - answer electrons
What type of magnet is used for the coil in a relay? - answer electromagnet
___ flow equals current flow. - answerElectron
When AC current passes through a circuit conductor or a connected load, it creates ___
that creates (or induces) a voltage in the circuit that actually opposes the applied
voltage. - answera magnetic field
A ___ is a device that converts electrical energy into a linear force. - answersolenoid
Two unlike poles of magnets brought together cause the magnets to ___ each other. -
answerattract
Permanent magnets are used in the construction of ___ motors.I. AC II. DC - answerII
only
Nonferrous materials, such as copper, ___ attracted by the magnetic field around a
magnet. - answerare not
A coil of wire wrapped around an iron core is a(n) ___ when it carries current. -
answerelectromagnet
Motors, circuit breakers, contactors, relays, and motor starters all use ___ principles. -
answerelectromagnetic
,The strength of the magnetic field around a coil (or winding) ___ when AC voltage is
applied. - answervaries
The basic law of magnetism states that unlike poles (south and north, for example) ___
each other. - answerattract
As two magnetic poles of the same polarity get closer together the force of ___ gets
stronger. - answerrepulsion
A coil of wire, when carrying current, acts like a ___. - answermagnet
The invisible magnetic lines that leave the north pole and enter the south pole of a
magnet are ___. - answerlines of flux
A ___ is a device that attracts iron and steel because of the molecular alignment of its
material. - answermagnet
Current flow through a conductor creates a magnetic field around the conductor. -
answerTrue
As current flow through a conductor increases, the magnetic field strength ___. -
answerincreases
The strength of the magnetic field around a coil (or winding) ___ when DC voltage is
applied. - answeris constant
If the current flowing through a coil of wire is increased, the magnetic field strength ___.
- answeralso increases
If a circuit is operating at 277 volts (RMS) the peak value of the voltage is ___ volts. -
answer391.8
Which of the symbols, shown below, is used to represent an AC power source in a
schematic circuit? - answer219.2 Q2 D
The term gigahertz means ___ per second. - answerbillion cycles
To an electrician the drawing at the right represents ___. - answera sine wave
One AC voltage cycle is completed in ___ degrees. - answer360
Each phase of three-phase AC power is offset by ___ degrees. - answer120
The horizontal axis on a voltage sine wave, generated from an AC generator,
represents ___. - answertime
,Which of the conversion formulas listed below is correct? - answerRMS = Peak x 0.707
RMS is an abbreviation for ___. - answerRoot Mean Square
A charged body is surrounded by ___. - answera magnetic field
___ is the output of an AC generator measured in cycles per second. -
answerFrequency
When two like-charged bodies are brought together, their magnetic fields will work to
___ them. - answerrepel
___ when current flows in a conductor. - answerboth a and b
The vertical axis on a voltage sine wave, generated from an AC generator, represents
___. - answervoltage
Where operating in the United States, AC voltage reaches a positive peak ___ times
during 1 second. - answer60
___ current constantly changes direction of flow and magnitude as it completes the
circuit from a power source to a load and then back to the power source. - answerAC
An AC generator produces ___ cycle(s) per revolution for each pair of poles. -
answerone
The peak-to-peak value of a sine wave is ___ the maximum positive peak value. -
answertwice
A capacitor is made up of a pair of conductive plates separated by a thin layer of ___
material. - answerinsulating
The magnetic field strength around a conductor is at its maximum when the AC current
is at ___ degrees. - answer90
___ is the property of an electrical circuit that opposes any change in current. -
answerInductance
Inductors in series add like resistors in ___. - answerseries
Which of the formulas, shown below, is correct to find the equivalent of 3 caps in a
parallel circuit? - answerCT=C1+C2+C3
Inductance is measured in ___. - answerHenrys
, A change in the magnetic field surrounding the conductor induces a voltage in the
conductor. This induced voltage is known as ___. - answerCounter EMF
___ is the measure of a circuit's ability to store an electrical charge. -
answerCapacitance
The unit of measure for capacitance is ___. - answerFarads
Which of the formulas, shown below, is correct to find the equivalent of 3 inductors in a
series circuit? - answerLT=L1+L2+L3
Inductors in parallel add like resistors in ___. - answerparallel
Which of the symbols, shown below, is used to represent a capacitor in a schematic
circuit? - answer219.3 Q 12 B
A lockout can be removed by ___. - answeronly the person who applied it
OSHA's Lockout/Tagout standards outline required measures for controlling hazardous
___ energies. - answerall of these
Use only Lockout/Tagout devices authorized for the particular equipment. These
devices are to be ___.I. standardized II. substantial III. durable - answerI, II & III
Insure that Lockout/Tagout devices identify the ___. - answerindividual
Compliance with Lockout/Tagout prevents an estimated ___ fatalities each year. -
answer120
___ is the property of an electrical circuit that opposes any change in current. -
answerInductance
Impedance is represented by the letter ___. - answerZ
In a purely capacitive circuit, current is said to ___ the applied source voltage. -
answerlead
The presence of inductive reactance in a circuit affects current flow. What is the
designated symbol for inductive reactance? - answerXL
In an inductive circuit, the current ___ the applied voltage. - answerlags
In an AC circuit containing resistance plus inductance, or resistance plus capacitance,
or resistance plus inductance and capacitance, the opposition to current flow is called
___. - answerimpedance
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