JATC - STUDY UNIT TEST 2 + 3
QUESTIONS AND ANSWERS
Electric Current - Correct Answers -The flow of electrons through a conductor.
Unit of Electric Current - Correct Answers -Ampere / A
Opposition to current flow - Correct Answers -Resistance / (R)
Unit of Electrical Potential - Correct Answers -Volt / V
Unit of Electrical Power - Correct Answers -Watt / W
Voltage in a given circuit is increased so current will - Correct Answers -Increase
Resistance is a given circuit is increased so current will - Correct Answers -Decrease
____ in a circuit is the amount of work being done per unit of time. - Correct Answers -
Power
One horsepower equals - Correct Answers -746 watts
Direct Current (DC) circuit, current flows - Correct Answers -Single direction
Alternating Current (AC) circuit, current flows - Correct Answers -Both direction
___ waveform will not cross the zero axis - Correct Answers -DC
___ waveform will cross the zero axis - Correct Answers -AC
Most common frequency in the US? - Correct Answers -60 Hz
Voltage Waveform with 60 Hz - Correct Answers -Completes 60 Hz cycles in 1 second.
___ is easier to transform - Correct Answers -AC Voltage
AC transformers allow - Correct Answers -Very high values to deliver large amounts of
power at low current levels.
, AC can easily transformed to - Correct Answers -Raise or lower levels of voltage and
current for a given amount of power.
When distributed by transmission lines, power loss is due to the ___ of the wire that
generates heat in the conductor. The heat is generated as a result of ___ flowing
through the conductor - Correct Answers -resistance / current
The ___ is the value of AC voltage that produces the same amount of power as a like
value of DC voltage. - Correct Answers -The RMS value
What does RMS stand for? - Correct Answers -Root Mean Square
Power - Correct Answers -The amount of work done per unit of time.
Conductor resistance causes a(n) ___ between the voltage source and the connected
load. - Correct Answers -Decrease in current
Power loss
Voltage drop
The power loss of a transmission line can be reduced by either reducing the ___ of the
wire or the amount of ___ . - Correct Answers -resistance / current
Reducing the resistance of the wire by one-half will reduce power loss by ___ , but
reducing the current by one-half will reduce the power loss by ___ - Correct Answers -
50% / 75%
By using transformers - Correct Answers -AC is converted from one level of voltage for
transmission and then reduced to a different level of voltage by the end-user.
Current and the Voltage since waves are in - phase - Correct Answers -They both have
the same frequency, crossing the reference line at the same time and going in the same
direction.
___ is used to supply over 90% of the world's electrical power requirements. - Correct
Answers -Alternating Current
What production of electrical current has a major influence on the effects of AC
Current? - Correct Answers -Time
Skin Effect - Correct Answers -The tendency of AC current to flow in the surface area of
a conductor and not evenly throughout the conductor.
Skin effect is caused by induced ___ from the AC current flow, which causes the
electrons to be repelled toward the outer surface of the conductor. - Correct Answers -
Eddy Currents
Skin Effect increases - Correct Answers -the effective resistance of the conductor.
QUESTIONS AND ANSWERS
Electric Current - Correct Answers -The flow of electrons through a conductor.
Unit of Electric Current - Correct Answers -Ampere / A
Opposition to current flow - Correct Answers -Resistance / (R)
Unit of Electrical Potential - Correct Answers -Volt / V
Unit of Electrical Power - Correct Answers -Watt / W
Voltage in a given circuit is increased so current will - Correct Answers -Increase
Resistance is a given circuit is increased so current will - Correct Answers -Decrease
____ in a circuit is the amount of work being done per unit of time. - Correct Answers -
Power
One horsepower equals - Correct Answers -746 watts
Direct Current (DC) circuit, current flows - Correct Answers -Single direction
Alternating Current (AC) circuit, current flows - Correct Answers -Both direction
___ waveform will not cross the zero axis - Correct Answers -DC
___ waveform will cross the zero axis - Correct Answers -AC
Most common frequency in the US? - Correct Answers -60 Hz
Voltage Waveform with 60 Hz - Correct Answers -Completes 60 Hz cycles in 1 second.
___ is easier to transform - Correct Answers -AC Voltage
AC transformers allow - Correct Answers -Very high values to deliver large amounts of
power at low current levels.
, AC can easily transformed to - Correct Answers -Raise or lower levels of voltage and
current for a given amount of power.
When distributed by transmission lines, power loss is due to the ___ of the wire that
generates heat in the conductor. The heat is generated as a result of ___ flowing
through the conductor - Correct Answers -resistance / current
The ___ is the value of AC voltage that produces the same amount of power as a like
value of DC voltage. - Correct Answers -The RMS value
What does RMS stand for? - Correct Answers -Root Mean Square
Power - Correct Answers -The amount of work done per unit of time.
Conductor resistance causes a(n) ___ between the voltage source and the connected
load. - Correct Answers -Decrease in current
Power loss
Voltage drop
The power loss of a transmission line can be reduced by either reducing the ___ of the
wire or the amount of ___ . - Correct Answers -resistance / current
Reducing the resistance of the wire by one-half will reduce power loss by ___ , but
reducing the current by one-half will reduce the power loss by ___ - Correct Answers -
50% / 75%
By using transformers - Correct Answers -AC is converted from one level of voltage for
transmission and then reduced to a different level of voltage by the end-user.
Current and the Voltage since waves are in - phase - Correct Answers -They both have
the same frequency, crossing the reference line at the same time and going in the same
direction.
___ is used to supply over 90% of the world's electrical power requirements. - Correct
Answers -Alternating Current
What production of electrical current has a major influence on the effects of AC
Current? - Correct Answers -Time
Skin Effect - Correct Answers -The tendency of AC current to flow in the surface area of
a conductor and not evenly throughout the conductor.
Skin effect is caused by induced ___ from the AC current flow, which causes the
electrons to be repelled toward the outer surface of the conductor. - Correct Answers -
Eddy Currents
Skin Effect increases - Correct Answers -the effective resistance of the conductor.
