Power Engineering 4a - Unit 8 –
Electro Technology Exam Questions
And Answers
/. When using Fleming's Left Hand Rule, the index finger represents
A) generator action flux direction.
B) motor action motion direction.
C) generator conductor motion direction.
D) motor action flux direction.
E) motor action direction of current flow. - Answer-✅D
/.A basic law of electricity is, unlike charges attract each other and like charges
A) impact each other.
B) hold each other.
C) attract each other.
D) are neutralized.
E) repel each other. - Answer-✅E
/.Some of the hazards of electrical transformer cooling oil can be compensated for by
adding
A) chelates.
B) anti-foaming substances.
C) chlorinated hydrocarbons.
D) Freon.
E) organic compounds. - Answer-✅C
/.Synchronous motors are used to
A) improve electrical system power factor.
B) bring up alternators to synchronous speed.
C) reduce the power factor for a power system.
D) eliminate the need for a DC power source.
E) drive a steam turbine. - Answer-✅A
/.A kilowatt-hour meter has a small motor which
A) turns at a constant speed.
B) slows down as power consumption increases.
C) has a speed proportional to power consumption.
D) moves the meter demand pointer.
E) indicates the multiplier to be used when reading the meter. - Answer-✅C
,/.The best type of diagram for showing electrical supply and distribution systems is the
A) process diagram.
B) single line diagram (one line).
C) elementary diagram.
D) piping diagram.
E) terminal and connection diagram. - Answer-✅B
/.In a 120/240 V one phase, three wire circuit, the color of the circuit conductor that is
grounded is
A) red.
B) white.
C) black.
D) blue.
E) green. - Answer-✅B
/.When disconnecting an alternator from the system, the first step should be
A) Open the circuit breaker first and then reduce the current of the alternator
B) Reduce the voltage to zero first and then open the circuit breaker
C) Reduce the alternator current first to zero and then open the main disconnecting
switch.
D) Reduce the current first and then reduce the voltage of the alternator
E) Reduce the speed of the alternator first and then open the circuit breaker. - Answer-
✅C
/.The use of electronic switches can result in excessively high transformer voltages due
to a phenomena called
A) capacitive reactance.
B) inductive reactance.
C) phase lag.
D) reactive voltage loss.
E) harmonic distortion. - Answer-✅E
/.A simple step-up transformer has a primary winding of 400 turns and a secondary
winding of 1800 turns. If the primary voltage is 440 volts, the voltage at the terminals of
the secondary winding will be
A) 880 V.
B) 1636 V.
C) 1800 V.
D) 1980 V.
E) 2000 V. - Answer-✅D
/.A megohmmeter measures
A) amperage.
B) megawatts of power.
C) resistance.
D) voltage drop.
, E) current flow. - Answer-✅C
/.The following materials have HIGH reluctance (select 3 correct answers):
A) iron
B) glass
C) steel
D) air
E) oil - Answer-✅B, D, E
/.The connection provided on DC motors to supply the armature with power
A) are slip rings.
B) are field poles.
C) is a rheostat.
D) is a commutator.
E) is a rotating conductor. - Answer-✅D
/.The common solution for armature reaction on large DC machines is
A) To install the interpoles
B) To install large field poles
C) To install small field poles
D) To laminate the field poles
E) To shift the field poles - Answer-✅A
/.When a material or substance does not form a magnetic flux easily it is said to have
high
A) permeability.
B) resistance.
C) reluctance.
D) field reactance.
E) magnetic flux density. - Answer-✅C
/.The brushes used to transfer power from armature are made up of carbon because
A) It has high coefficient of friction and is good conductor of electricity
B) It has low coefficient of friction and bad conductor of electricity
C) It has low coefficient of friction and is good conductor of electricity
D) It is good conductor of electricity and easy to replace
E) It does not wear out easily - Answer-✅C
/.Current flow direction and intensity will
A) affect magnetic field direction and intensity.
B) affect the voltage.
C) affect the resistance of a circuit.
D) not affect electromagnetic field direction.
E) not affect electromagnetic field intensity. - Answer-✅A
Electro Technology Exam Questions
And Answers
/. When using Fleming's Left Hand Rule, the index finger represents
A) generator action flux direction.
B) motor action motion direction.
C) generator conductor motion direction.
D) motor action flux direction.
E) motor action direction of current flow. - Answer-✅D
/.A basic law of electricity is, unlike charges attract each other and like charges
A) impact each other.
B) hold each other.
C) attract each other.
D) are neutralized.
E) repel each other. - Answer-✅E
/.Some of the hazards of electrical transformer cooling oil can be compensated for by
adding
A) chelates.
B) anti-foaming substances.
C) chlorinated hydrocarbons.
D) Freon.
E) organic compounds. - Answer-✅C
/.Synchronous motors are used to
A) improve electrical system power factor.
B) bring up alternators to synchronous speed.
C) reduce the power factor for a power system.
D) eliminate the need for a DC power source.
E) drive a steam turbine. - Answer-✅A
/.A kilowatt-hour meter has a small motor which
A) turns at a constant speed.
B) slows down as power consumption increases.
C) has a speed proportional to power consumption.
D) moves the meter demand pointer.
E) indicates the multiplier to be used when reading the meter. - Answer-✅C
,/.The best type of diagram for showing electrical supply and distribution systems is the
A) process diagram.
B) single line diagram (one line).
C) elementary diagram.
D) piping diagram.
E) terminal and connection diagram. - Answer-✅B
/.In a 120/240 V one phase, three wire circuit, the color of the circuit conductor that is
grounded is
A) red.
B) white.
C) black.
D) blue.
E) green. - Answer-✅B
/.When disconnecting an alternator from the system, the first step should be
A) Open the circuit breaker first and then reduce the current of the alternator
B) Reduce the voltage to zero first and then open the circuit breaker
C) Reduce the alternator current first to zero and then open the main disconnecting
switch.
D) Reduce the current first and then reduce the voltage of the alternator
E) Reduce the speed of the alternator first and then open the circuit breaker. - Answer-
✅C
/.The use of electronic switches can result in excessively high transformer voltages due
to a phenomena called
A) capacitive reactance.
B) inductive reactance.
C) phase lag.
D) reactive voltage loss.
E) harmonic distortion. - Answer-✅E
/.A simple step-up transformer has a primary winding of 400 turns and a secondary
winding of 1800 turns. If the primary voltage is 440 volts, the voltage at the terminals of
the secondary winding will be
A) 880 V.
B) 1636 V.
C) 1800 V.
D) 1980 V.
E) 2000 V. - Answer-✅D
/.A megohmmeter measures
A) amperage.
B) megawatts of power.
C) resistance.
D) voltage drop.
, E) current flow. - Answer-✅C
/.The following materials have HIGH reluctance (select 3 correct answers):
A) iron
B) glass
C) steel
D) air
E) oil - Answer-✅B, D, E
/.The connection provided on DC motors to supply the armature with power
A) are slip rings.
B) are field poles.
C) is a rheostat.
D) is a commutator.
E) is a rotating conductor. - Answer-✅D
/.The common solution for armature reaction on large DC machines is
A) To install the interpoles
B) To install large field poles
C) To install small field poles
D) To laminate the field poles
E) To shift the field poles - Answer-✅A
/.When a material or substance does not form a magnetic flux easily it is said to have
high
A) permeability.
B) resistance.
C) reluctance.
D) field reactance.
E) magnetic flux density. - Answer-✅C
/.The brushes used to transfer power from armature are made up of carbon because
A) It has high coefficient of friction and is good conductor of electricity
B) It has low coefficient of friction and bad conductor of electricity
C) It has low coefficient of friction and is good conductor of electricity
D) It is good conductor of electricity and easy to replace
E) It does not wear out easily - Answer-✅C
/.Current flow direction and intensity will
A) affect magnetic field direction and intensity.
B) affect the voltage.
C) affect the resistance of a circuit.
D) not affect electromagnetic field direction.
E) not affect electromagnetic field intensity. - Answer-✅A
