Stationary Engineer Electric questions with
correct answers
An AC circuit consists only of a pure inductance and a power source. The
relationship between the voltage and the current in this circuit is that
the - current lags the voltage
The power factor of a load is equal to the ____________ power divided
by the ____________ power. - True ; apparent
A 10-ohms and 20-ohms resistor are connected in parallel. The total line
current drawn by this parallel combination is 30 amps. Under these
conditions, the line voltage will be ____________ volts. - 200
A 20-ohm resistor is connected in series with a parallel combination of
two resistors, one of which is 10-ohms, the other 40-ohms. If the voltage
across the parallel combination is 40 volts, the voltage across the 20 -
ohm series resistor is ________ volts. - 100
A certain 120-volts single-phase AC circuit has a power factor of 80
percent and a watt-meter reading of 1150 watts. The current drawn by
the circuit is _________ amperes. - 12
,If the voltage between lines of a 3-phase, 3-wire delta connected system
is 2400 volts, then the phase voltage is _____________ volts - 2400
A circuit consists of an inductive reactance of 15 ohms and a resistor of
20 ohms in series across a 100-volts, 60 cycles AC supply. The current in
this circuit is ____________ amperes. - 4
A 3 phase, 3 wire, 208 volt, 60 cycles AC service supplies a balanced load
consisting of three 30 ohms resistors connected wye. The line current
under these conditions os MOST NEARLY ___________ amperes. - 6.9
If the level of the electrolyte in a lead acid storage battery falls below
the top of the plates because of evaporations under normal operating
conditions, it is BEST to add - Water
A 600 volt cartridge fuse must have knife blade contacts if its current
rating exceeds _____________ amperes. - 60
When the magnitude of the short circuit currents in a feeder circuit must
be limited, this is USUALLY accomplished by means of - reactors
The cross sectional area in circular mils of a standard cable having 37
strands, each of which ha a diameter of 90 nils, is MOST NEARLY -
300,000
,A coil having an average diameter of 4 inches is to be made up from a
1,260 ft long length of wire. The numbers of turns in this coil will be
MOST NEARLY - 1,200
The device commonly known as a growler is FREQUENTLY used to - test
DC armature windings for shorts
When a megger is applied alternately to the two leads of a direct current
electrolytic capacitor, the reading will - start at zero but increase
gradually for one of the connections
The device used to convert direct current to alternating current is called
- inverters
Of the following conditions, the one which is MOST likely to cause
flashing or excessive arcing from brush to brush in a motor is -
Excessively high voltage on the line
The currents in the armature equalizer connections in a DC generator
are - alternating currents
A generating station has one 1000 Kw and two 2000 Kw generators. To
supply 2000 Kw MOST economically, the operating conditions should be -
one 2000 Kw generator at full load
, The terminal voltage of a DC shunt generator having an armature current
of 100 amperes, an armature resistance of 0.02 ohms, and a generated
E.M.F of 222 volts is MOST NEARLY ______________ volts. - 220
The number of poles in the field of an alternator generating voltage at a
frequency of 60 cycles per second while rotating at 1200 rpm is - 6
If the field of a shunt motor opens while running, the motor will - run
away
To reverse the direction of rotation of a cumulative compound motor,
and not have it run as a differential compound motor, reverse the
connections to the ____________ field. - shunt field and to the series
A main contributing factor to motor stator failure usually is - dirt
The input of a motor is 40,000 watts and efficiency is 80 percent. The
TOTAL energy loss is __________ watts. - 8,000
The full load current of a three-phase 5 hp motor operating at 200 volts,
60 cycles, and having an efficiency of 80 percent and a power factor of
85 percent is MOST NEARLY ____________ amperes. - 14.4
Of the following motors, the one that has the best speed regulation is
the motor. - shunt
correct answers
An AC circuit consists only of a pure inductance and a power source. The
relationship between the voltage and the current in this circuit is that
the - current lags the voltage
The power factor of a load is equal to the ____________ power divided
by the ____________ power. - True ; apparent
A 10-ohms and 20-ohms resistor are connected in parallel. The total line
current drawn by this parallel combination is 30 amps. Under these
conditions, the line voltage will be ____________ volts. - 200
A 20-ohm resistor is connected in series with a parallel combination of
two resistors, one of which is 10-ohms, the other 40-ohms. If the voltage
across the parallel combination is 40 volts, the voltage across the 20 -
ohm series resistor is ________ volts. - 100
A certain 120-volts single-phase AC circuit has a power factor of 80
percent and a watt-meter reading of 1150 watts. The current drawn by
the circuit is _________ amperes. - 12
,If the voltage between lines of a 3-phase, 3-wire delta connected system
is 2400 volts, then the phase voltage is _____________ volts - 2400
A circuit consists of an inductive reactance of 15 ohms and a resistor of
20 ohms in series across a 100-volts, 60 cycles AC supply. The current in
this circuit is ____________ amperes. - 4
A 3 phase, 3 wire, 208 volt, 60 cycles AC service supplies a balanced load
consisting of three 30 ohms resistors connected wye. The line current
under these conditions os MOST NEARLY ___________ amperes. - 6.9
If the level of the electrolyte in a lead acid storage battery falls below
the top of the plates because of evaporations under normal operating
conditions, it is BEST to add - Water
A 600 volt cartridge fuse must have knife blade contacts if its current
rating exceeds _____________ amperes. - 60
When the magnitude of the short circuit currents in a feeder circuit must
be limited, this is USUALLY accomplished by means of - reactors
The cross sectional area in circular mils of a standard cable having 37
strands, each of which ha a diameter of 90 nils, is MOST NEARLY -
300,000
,A coil having an average diameter of 4 inches is to be made up from a
1,260 ft long length of wire. The numbers of turns in this coil will be
MOST NEARLY - 1,200
The device commonly known as a growler is FREQUENTLY used to - test
DC armature windings for shorts
When a megger is applied alternately to the two leads of a direct current
electrolytic capacitor, the reading will - start at zero but increase
gradually for one of the connections
The device used to convert direct current to alternating current is called
- inverters
Of the following conditions, the one which is MOST likely to cause
flashing or excessive arcing from brush to brush in a motor is -
Excessively high voltage on the line
The currents in the armature equalizer connections in a DC generator
are - alternating currents
A generating station has one 1000 Kw and two 2000 Kw generators. To
supply 2000 Kw MOST economically, the operating conditions should be -
one 2000 Kw generator at full load
, The terminal voltage of a DC shunt generator having an armature current
of 100 amperes, an armature resistance of 0.02 ohms, and a generated
E.M.F of 222 volts is MOST NEARLY ______________ volts. - 220
The number of poles in the field of an alternator generating voltage at a
frequency of 60 cycles per second while rotating at 1200 rpm is - 6
If the field of a shunt motor opens while running, the motor will - run
away
To reverse the direction of rotation of a cumulative compound motor,
and not have it run as a differential compound motor, reverse the
connections to the ____________ field. - shunt field and to the series
A main contributing factor to motor stator failure usually is - dirt
The input of a motor is 40,000 watts and efficiency is 80 percent. The
TOTAL energy loss is __________ watts. - 8,000
The full load current of a three-phase 5 hp motor operating at 200 volts,
60 cycles, and having an efficiency of 80 percent and a power factor of
85 percent is MOST NEARLY ____________ amperes. - 14.4
Of the following motors, the one that has the best speed regulation is
the motor. - shunt
