Stationary Engineer Electric Exam Questions with 100% Correct Answers (A+ Graded)
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Course
Stationary Engineer Electric
Institution
Stationary Engineer Electric
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 Correct Answer current lags the voltage
The power factor of a load is equal to the ____________ power divided by the ____________ power. Correct A...
Stationary Engineer Electric Exam Questions
with 100% Correct Answers (A+ Graded)
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 Correct Answer current lags the voltage
The power factor of a load is equal to the ____________ power divided by the ____________ power. Correct 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. Correct 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.
Correct 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. Correct 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 Correct 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. Correct 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. Correct 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 Correct Answer Water
A 600 volt cartridge fuse must have knife blade contacts if its current rating exceeds _____________ amperes. Correct Answer 60
When the magnitude of the short circuit currents in a feeder circuit must be limited, this is USUALLY accomplished by means of Correct 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 Correct 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 Correct Answer 1,200
The device commonly known as a growler is FREQUENTLY used to Correct 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 Correct Answer start at zero but increase gradually for one of the connections
The device used to convert direct current to alternating current is called Correct 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 Correct Answer Excessively high voltage on the
line
The currents in the armature equalizer connections in a DC generator are Correct 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 Correct 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. Correct 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 Correct Answer 6
If the field of a shunt motor opens while running, the motor will Correct 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. Correct Answer shunt field and to the series
A main contributing factor to motor stator failure usually is Correct Answer dirt
The input of a motor is 40,000 watts and efficiency is 80 percent. The TOTAL energy loss is __________ watts. Correct 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. Correct Answer 14.4
Of the following motors, the one that has the best speed regulation is the motor. Correct
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 Correct Answer 1080
Of the following, a MAJOR advantage of an AC synchronous motor is that it(s) Correct 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 Correct 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 Correct Answer KVA rating
A transformer rates at 200 KVA is FULLY loaded with a lagging power factor of 80% when it is supplying Correct 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. Correct Answer 25
Assume that a switchboard ammeter which is connected to a current transformer is damaged and must be removed without interrupting the service. Of the following, an ESSENTIAL precaution to be taken before disconnecting the ammeter is to Correct Answer short the secondary of the transformer
A DC relay is rated at 6 volts and 120 ohms. This relay can be operated from a 120 volt line by connecting a ___________ ohm resistance in __________ with relay Correct Answer 2280: series
Some relays are provided with dash-pots. The FUNCTION of these dash-pots is to provide Correct Answer delayed time action
An ammeter has a full scale deflection for a current of 0.01 amperes and an internal resistance of 20 ohms. In order to have the ammeter read full-scale for a current of 10 amperes and not damage its movement, a shunt should be used having a value of__________ ohms. Correct Answer 0.02
An air circuit breaker has contacts that flash. The MOST probable cause of this trouble is that the Correct Answer barriers are broken
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