EWRB THEORY COMPREHENSIVE EXAM 2026
QUESTIONS AND SOLUTIONS RATED A+
✔✔which component of a three phase induction motor houses the stator windings
stator
rotor
slip rings
commutator - ✔✔stator
✔✔is there a neutral in a 3 phase motor - ✔✔false
✔✔true or false, universal motors can run at speeds exceeding 10,000 RPM - ✔✔true
✔✔true or false, isolating transformers are primarily used to improve energy efficiency
in electrical systems - ✔✔false
✔✔what is the defenition of transformers - ✔✔a electrical device that uses
electromagnetic induction to transfer electrical energy between two or more circuits
typically by stepping up or stepping down the voltage to AC current
✔✔which single phase motor type is generally used in applications like electric shavers
and hair dryers
.synchronous motor
.universal motor
.shaded pole motor
.capacitor start motor - ✔✔universal motor
✔✔which conditions contribute to the severity of an electric shock
.length of the conductors
.current magnitude
.duration of contact
.cable insulation colour - ✔✔current magnitude and duration of contact
✔✔a 230v electric heater operates in the high heat mode with an effective resistance of
46ohm what is the power consumed by the heater
.2000w
.800w
.1150w
.1500w - ✔✔1150w
✔✔if a 100w light bulb operates for 2 hours how much energy does it consume in watt
hours - ✔✔200
✔✔by rearranging the six winding terminations how can a motor be configured
,.only delta connection
.parallel connection
.only star connection
.either star or delta connection - ✔✔either star or delta connection
✔✔contacting active phase and earth conductors simultaneously is less dangerous than
phase and neutral contact true or false - ✔✔false
✔✔what is a typical application for a totally enclosed fan cooked TEFC motor
.environments with explosive gases
.industrial machinery requiring protection from dust and moisture
.submersible pumps
.indoor appliances with minimal dust exposure - ✔✔industrial machinery requiring
protection from dust and moisture
✔✔which part of a three phase induction motor is typically made of laminated iron to
reduce eddy currents
.bearings
.iron circuit
.rotor bars
.end caps - ✔✔iron circuit
✔✔which safety measure is not part of ensuring workplace safety
.minimising risks
.ignoring risks
.eliminating hazards
.identifying hazards - ✔✔ignoring risks
✔✔which group benefits from implementing safe work practices
visitors only
only supervisors
electrical workers and the public
no one specifically - ✔✔electrical workers and the public
✔✔why is 500v dc used for insulation resistance tests
to increase current flow
to reduce voltage drops
to detect insulation weakness effectively
to stabilise power output - ✔✔to detect insulation weakness effectively
✔✔what tools are critical for high voltage work
regular shoes
insulated mats
harnesses
,non insulated tools - ✔✔insulated mats
harnesses
✔✔true or false a remote stop start station allows control of the motor from a distant
location - ✔✔true
✔✔true or false effectiveness of controls and safety devices must be tested in
appliances - ✔✔true
✔✔if the impedance (z) is 50ohm and the current (i) is 2A what is the voltage (V) -
✔✔100v
✔✔which of the following is not a purpose of the men system
.maintaining a low impedance return path
.rapid fault disconnection
.ensuring voltage stability
.increasing voltage above 230v - ✔✔increasing voltage above 230v
✔✔what are two factors that determine the temperature rating of flexible cables
length on conductor
ambient conditions
cross sectional area
insulation colour - ✔✔ambient conditions, cross sectional area
✔✔what testing standards is used for portable RCDs
AS/NZS 3760
BS88
AS/NZS 3000
IEC 60269 - ✔✔AS/NZS 3760
✔✔true or false in a permanently split capacitor motor, the capacitor remains in the
circuit during both starting and running - ✔✔true
✔✔true or false stored energy in capacitors can cause harm even after disconnection -
✔✔true
✔✔true or false flexible cords are typically made with twisted parallel and circular
construction - ✔✔true
✔✔true or false a phase rotation meter is essential for working three phase systems -
✔✔true
, ✔✔true or false an isolating transformer ensures safety by providing no direct electrical
connection between its primary and secondary windings - ✔✔true
✔✔what's a example of proper safety tagging
.allowing multiple workers to share one tag
. skipping tag placement in emergencies
.placing a personal danger tag during maintenance
removing tag before testing - ✔✔placing a personal danger tag during maintenance
removing
✔✔what fault can occur if the start winding in incorrectly connected to the centrifugal
switch in a single phase motor
.motor speed increases beyond rated speed
.motor operates normally
.motor fails to start or starts erratically
.motor runs at higher efficiency - ✔✔motor fails to start or starts erratically
✔✔true or false a properly configured men system ensures reliable protective device
operation - ✔✔true
✔✔in a DC circuit a 12v battery supplies three resistors R1 24ohm is in parallel with R2
48ohm and this combination is in series with R3 12ohm, what is the total resistance of
the circuit
.36ohm
.28ohm
.32ohm
.24ohm - ✔✔28 ohm
✔✔in a series circuit if one component fails what happens to the circuit
.only the failed component stops working
.the entire circuit stops functioning
.the voltage increases across the remaining components
.the rest of the circuit continues to operate - ✔✔the entire circuit stops operating
✔✔what is the purpose of ensuring conductor protection during disconnection
.to prevent mechanical damage or interference
. to increase current capacity
.to reduce voltage loss
. to enhance circuit efficiency - ✔✔to prevent mechanical damage or interference
✔✔what is the purpose of written isolation procedures
to stabilise voltage circuits
to enhance current flow
to reduce power consumption
QUESTIONS AND SOLUTIONS RATED A+
✔✔which component of a three phase induction motor houses the stator windings
stator
rotor
slip rings
commutator - ✔✔stator
✔✔is there a neutral in a 3 phase motor - ✔✔false
✔✔true or false, universal motors can run at speeds exceeding 10,000 RPM - ✔✔true
✔✔true or false, isolating transformers are primarily used to improve energy efficiency
in electrical systems - ✔✔false
✔✔what is the defenition of transformers - ✔✔a electrical device that uses
electromagnetic induction to transfer electrical energy between two or more circuits
typically by stepping up or stepping down the voltage to AC current
✔✔which single phase motor type is generally used in applications like electric shavers
and hair dryers
.synchronous motor
.universal motor
.shaded pole motor
.capacitor start motor - ✔✔universal motor
✔✔which conditions contribute to the severity of an electric shock
.length of the conductors
.current magnitude
.duration of contact
.cable insulation colour - ✔✔current magnitude and duration of contact
✔✔a 230v electric heater operates in the high heat mode with an effective resistance of
46ohm what is the power consumed by the heater
.2000w
.800w
.1150w
.1500w - ✔✔1150w
✔✔if a 100w light bulb operates for 2 hours how much energy does it consume in watt
hours - ✔✔200
✔✔by rearranging the six winding terminations how can a motor be configured
,.only delta connection
.parallel connection
.only star connection
.either star or delta connection - ✔✔either star or delta connection
✔✔contacting active phase and earth conductors simultaneously is less dangerous than
phase and neutral contact true or false - ✔✔false
✔✔what is a typical application for a totally enclosed fan cooked TEFC motor
.environments with explosive gases
.industrial machinery requiring protection from dust and moisture
.submersible pumps
.indoor appliances with minimal dust exposure - ✔✔industrial machinery requiring
protection from dust and moisture
✔✔which part of a three phase induction motor is typically made of laminated iron to
reduce eddy currents
.bearings
.iron circuit
.rotor bars
.end caps - ✔✔iron circuit
✔✔which safety measure is not part of ensuring workplace safety
.minimising risks
.ignoring risks
.eliminating hazards
.identifying hazards - ✔✔ignoring risks
✔✔which group benefits from implementing safe work practices
visitors only
only supervisors
electrical workers and the public
no one specifically - ✔✔electrical workers and the public
✔✔why is 500v dc used for insulation resistance tests
to increase current flow
to reduce voltage drops
to detect insulation weakness effectively
to stabilise power output - ✔✔to detect insulation weakness effectively
✔✔what tools are critical for high voltage work
regular shoes
insulated mats
harnesses
,non insulated tools - ✔✔insulated mats
harnesses
✔✔true or false a remote stop start station allows control of the motor from a distant
location - ✔✔true
✔✔true or false effectiveness of controls and safety devices must be tested in
appliances - ✔✔true
✔✔if the impedance (z) is 50ohm and the current (i) is 2A what is the voltage (V) -
✔✔100v
✔✔which of the following is not a purpose of the men system
.maintaining a low impedance return path
.rapid fault disconnection
.ensuring voltage stability
.increasing voltage above 230v - ✔✔increasing voltage above 230v
✔✔what are two factors that determine the temperature rating of flexible cables
length on conductor
ambient conditions
cross sectional area
insulation colour - ✔✔ambient conditions, cross sectional area
✔✔what testing standards is used for portable RCDs
AS/NZS 3760
BS88
AS/NZS 3000
IEC 60269 - ✔✔AS/NZS 3760
✔✔true or false in a permanently split capacitor motor, the capacitor remains in the
circuit during both starting and running - ✔✔true
✔✔true or false stored energy in capacitors can cause harm even after disconnection -
✔✔true
✔✔true or false flexible cords are typically made with twisted parallel and circular
construction - ✔✔true
✔✔true or false a phase rotation meter is essential for working three phase systems -
✔✔true
, ✔✔true or false an isolating transformer ensures safety by providing no direct electrical
connection between its primary and secondary windings - ✔✔true
✔✔what's a example of proper safety tagging
.allowing multiple workers to share one tag
. skipping tag placement in emergencies
.placing a personal danger tag during maintenance
removing tag before testing - ✔✔placing a personal danger tag during maintenance
removing
✔✔what fault can occur if the start winding in incorrectly connected to the centrifugal
switch in a single phase motor
.motor speed increases beyond rated speed
.motor operates normally
.motor fails to start or starts erratically
.motor runs at higher efficiency - ✔✔motor fails to start or starts erratically
✔✔true or false a properly configured men system ensures reliable protective device
operation - ✔✔true
✔✔in a DC circuit a 12v battery supplies three resistors R1 24ohm is in parallel with R2
48ohm and this combination is in series with R3 12ohm, what is the total resistance of
the circuit
.36ohm
.28ohm
.32ohm
.24ohm - ✔✔28 ohm
✔✔in a series circuit if one component fails what happens to the circuit
.only the failed component stops working
.the entire circuit stops functioning
.the voltage increases across the remaining components
.the rest of the circuit continues to operate - ✔✔the entire circuit stops operating
✔✔what is the purpose of ensuring conductor protection during disconnection
.to prevent mechanical damage or interference
. to increase current capacity
.to reduce voltage loss
. to enhance circuit efficiency - ✔✔to prevent mechanical damage or interference
✔✔what is the purpose of written isolation procedures
to stabilise voltage circuits
to enhance current flow
to reduce power consumption
