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Stationary Engineer Electric fully solved & verified actual exam(download to pass).
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Stationary Engineer Electricfully solved & verified actual
exam(download to pass)
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 - answer current lags the voltage
The power factor of a load is equal to the ____________ power divided
by the ____________ power. - answer 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. - answer
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. - answer 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. - answer 12
If the voltage between lines of a 3-phase, 3-wire delta connected
system is 2400 volts, then the phase voltage is _____________ volts -
answer 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. - answer 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.
- answer 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 - answer Water
A 600 volt cartridge fuse must have knife blade contacts if its
current rating exceeds _____________ amperes. - answer 60
When the magnitude of the short circuit currents in a feeder circuit
must be limited, this is USUALLY accomplished by means of - answer
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 -
answer 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 - answer 1,200
The device commonly known as a growler is FREQUENTLY used to -
answer 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 - answer start at
zero but increase gradually for one of the connections
,The device used to convert direct current to alternating current is
called - answer 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 -
answer Excessively high voltage on the line
The currents in the armature equalizer connections in a DC
generator are - answer 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 - answer 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. -
answer 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
- answer 6
If the field of a shunt motor opens while running, the motor will -
answer 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. - answer shunt field and to
the series
A main contributing factor to motor stator failure usually is - answer
dirt
, The input of a motor is 40,000 watts and efficiency is 80 percent.
The TOTAL energy loss is __________ watts. - answer 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. - answer
14.4
Of the following motors, the one that has the best speed regulation
is the motor. - answer shunt
The full load speed of a 60-cycle 208 volt, 3 phase induction motor
having 6 poles and operating with a slip of 10% is MOST
NEARLY___________ r.p.m - answer 1080
Of the following, a MAJOR advantage of an AC synchronous motor is
that it(s) - answer can be used for power factor correction
If the field current of a synchronous motor is increased to a point
which makes the synchronous motor overexcited, the - answer
motor will take a leading current
When transformers are to be operated in parallel, it is NOT
necessary that the transformer have the same - answer KVA rating
A transformer rates at 200 KVA is FULLY loaded with a lagging
power factor of 80% when it is supplying - answer 160 KW
If the current in the primary of a current transformer is 500 amperes
and the transformer has a ratio of 100 to 5, an ammeter connected
to the secondary will read MOST NEARLY___________ amperes. -
answer 25
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