Exam Questions and CORRECT Answers
In a 60 Hertz system, the voltage will go to "0" ___ times per second? - CORRECT
ANSWER - D.
120
What type of magnet is used for the coil in a relay? - CORRECT ANSWER - C.
electromagnet
___ flow equals current flow. - CORRECT ANSWER - C.
Electron
______ 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." - CORRECT ANSWER - D.
Coulomb's
If the RMS value is 125 volts, what is the peak value? - CORRECT ANSWER - D.
176.75
If the RMS value is 125 volts, what is the peak value? - CORRECT ANSWER - D.
176.75
Which of the symbols, shown below, is used to represent an inductor in a schematic circuit? -
CORRECT ANSWER - C.
Electrical current is the flow of ___. - CORRECT ANSWER - B.
electrons
,Which of the formulas, shown below, is correct to find the total of three capacitors in a series
circuit? - CORRECT ANSWER - B.
Which of the formulas, shown below, is correct to find the equivalent of three inductors in a
parallel circuit? - CORRECT ANSWER - A.
As current flow through a conductor increases, the magnetic field strength ___. - CORRECT
ANSWER - C.
increases
Current flow through a conductor creates a magnetic field around the conductor. - CORRECT
ANSWER - B.
True
A change in the magnetic field surrounding the conductor induces a voltage in the conductor.
This induced voltage is known as ___. - CORRECT ANSWER - B.
Counter EMF
A ___ is a device that converts electrical energy into a linear force. - CORRECT ANSWER -
D.
solenoid
A ___ is a device that attracts iron and steel because of the molecular alignment of its material. -
CORRECT ANSWER - D.
magnet
Nonferrous materials, such as copper, ___ attracted by the magnetic field around a magnet. -
CORRECT ANSWER - B.
are not
,Permanent magnets are used in the construction of ___ motors.I. AC II. DC - CORRECT
ANSWER - D.
II only
The invisible magnetic lines that leave the north pole and enter the south pole of a magnet are
___. - CORRECT ANSWER - A.
lines of flux
Two unlike poles of magnets brought together cause the magnets to ___ each other. - CORRECT
ANSWER - C.
attract
The basic law of magnetism states that unlike poles (south and north, for example) ___ each
other. - CORRECT ANSWER - A.
attract
As two magnetic poles of the same polarity get closer together the force of ___ gets stronger. -
CORRECT ANSWER - B.
repulsion
If the current flowing through a coil of wire is increased, the magnetic field strength ___. -
CORRECT ANSWER - C.
also increases
A coil of wire, when carrying current, acts like a ___. - CORRECT ANSWER - B.
magnet
A coil of wire wrapped around an iron core is a(n) ___ when it carries current. - CORRECT
ANSWER - D.
, electromagnet
The strength of the magnetic field around a coil (or winding) ___ when AC voltage is applied. -
CORRECT ANSWER - B.
varies
The strength of the magnetic field around a coil (or winding) ___ when DC voltage is applied. -
CORRECT ANSWER - A.
is constant
Motors, circuit breakers, contactors, relays, and motor starters all use ___ principles. -
CORRECT ANSWER - C.
electromagnetic
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. -
CORRECT ANSWER - D.
a magnetic field
When current passes through a conductor, a magnetic field is created around the conductor.
When individual circuit conductors are either in close proximity (in wireways, trenches, cable
trays, etc) or contained in the same cable or conduit, these magnetic fields cancel each other
because the currents in each conductor are not in phase with each other. - CORRECT
ANSWER - A.
True
The term gigahertz means ___ per second. - CORRECT ANSWER - C.
billion cycles
___ when current flows in a conductor. - CORRECT ANSWER - C.
both a and b