Description : An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, the cycles will _____________. A. remain at 60 Hz B. increase to 61 Hz C. decrease to 59 Hz D. increase to 63 Hz
Last Answer : Answer: B
Description : When shore power is being connected to a ship in dry dock, _____________. A. the ship's generators are paralleled with the shore power to provide continuous power B. proper phase sequence must be ... 450 volts must be supplied from the shore D. exactly 60 Hz must be provided by the terminal
Description : If there is a reduction in the normally supplied frequency to a 120/240 volt, threephase AC current motor from 60 hertz to 55 hertz, the motor would _____________. A. run at a slower speed B. operate at a lower current C. overheat D. trip off the line
Last Answer : Answer: A
Description : In the flow of one cycle of single phase AC current past any given point in a circuit, the maximum current peak occurs _____________. A. one time B. two times C. three times D. four times
Description : If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC
Last Answer : Answer: D
Description : The standard method of controlling the output voltage of a 440 volt, 60 Hz, AC generator is accomplished by adjusting the ____________. A. prime mover speed droop B. number of poles C. alternator field excitation D. load on the alternator
Last Answer : Answer: C
Description : The output voltage of a 440 volt, 60 Hz AC generator is controlled by the ______________. A. load on the alternator B. load on the prime mover C. speed of the prime mover D. exciter output voltage
Description : If a delicate component must be soldered into a circuit, the component may be protected from the heat of the soldering process by _____________. A. operating the soldering gun not more than 60 seconds at ... oxidizing the leads to be soldered D. coating the leads to be soldered with a light oil film
Description : For more complete vessel protection when using an impressed current cathodic system _____________. A. all ship's service alternators have additional temperature sensing devices and a thermal recorder ... with the hull and the propeller shaft is grounded through a slip ring/brush arrangement
Description : The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the _____________. A. prime mover speed B. exciter output voltage C. load on the alternator D. number of poles
Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work
Description : In an AC generator, direct current from a separate source is passed through the windings of the rotor _____________. A. by means of slip rings and brushes B. by means of a commutator C. by means of rotating bar magnet D. to minimize the danger of arc over
Description : The number of cycles per second occurring in AC voltage is known as the _____________. A. phase angle B. frequency C. wave form D. half mode
Description : The electrical schematic shown in the illustration indicates the lighting feeder circuit is _____________. EL-0014 A. three phase, 450 volt, and 60 cycle B. three phase, 120 volt, and 60 cycle C. single phase, 120 volt, and 60 cycle D. not specified
Description : If the electricity represented by the wave form in 'B' were applied to the left side of the illustrated circuit, the output on the right side would be ____________. EL-0064 A. direct current with the ... lower lead D. clipped to a value equal to the square root of 3 times the input voltage value
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Description : A sinusoidally alternating current of frequency 60 Hz has a maximum value of 15 A. Find the value of current after 1/200 second
Last Answer : A sinusoidally alternating current of frequency 60 Hz has a maximum value of 15 A. Find the value of current after 1/200 second
Description : In accordance with Coast Guard Regulations (46 CFR), a circuit breaker located in the machinery space and installed in a 440V AC system must _____________. A. be dependent upon mechanical ... the maximum asymmetrical shortcircuit current available at the point of application D. all of the above
Description : As an armature revolves within a magnetic field, friction is developed between the rotated magnetized particles as they pass through each magnetization cycle. This results in ____________. A. copper loss B. eddy-current loss C. hysteresis loss D. armature reaction
Description : As shown in the illustration, the circuit has been on the line for several days when component 'E1' burns out. The operator receives an alarm, switches over 'B' to energize the standby ... than required for the circuit therefore limiting the current through the alarm relay which will not pick up
Description : If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18
Description : The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be (A) 3.6 V. (B) 2.5 V. (C) 3.0 V. (D) 6.0 V.
Last Answer : (C) 3.0 V.
Description : If an AC generator experiences voltage failure, the cause may be _____________. A. an open in the field circuit B. the brushes shifting out of the neutral plane C. excessive locked-rotor current D. a rotating slip ring
Description : Universal motors will operate on AC or DC current, and are generally found in _____________. A. portable tools B. large pump motors C. turbo electric main motors D. forced draft fans
Description : A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an _____________. A. rotor B. stator C. exciter D. armature
Description : The hook-on AC volt-ammeter consists essentially of a split-core and a rectifiertype instrument connected to the secondary winding of a _____________. A. potential transformer B. control transformer C. current transformer D. reactance transformer
Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming ... hazardous condition will be created by the incoming machine being at a higher frequency than the bus
Description : When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is _____________. A. lagging B. leading C. maximum D. minimum
Description : When the voltage and the current developed in an AC circuit reach their peak values at the same time, the power factor is considered to be _____________. A. lagging B. leading C. unity D. infinity
Description : Equal power factors on paralleled AC generators are maintained by an automatic _____________. A. voltage regulator B. reverse power relay C. reverse current relay D. governor control switch
Description : When measuring AC current flow, you must always connect the meter _____________. A. in series with the power source and load B. in parallel with the power source and load C. insuring correct polarity D. using the lowest range possible to prevent instrument damage
Description : Capacitance in an AC circuit will _____________. A. stop current flow once the capacitor is fully charged B. allow current flow in only one direction C. oppose any change in circuit voltage D. rectify the current
Description : The electrical supply applied to the anodes shown in the illustration is _____________. EL-0090 A. low voltage, high current DC B. low voltage, high current AC C. high voltage, low current DC D. high voltage, low current AC
Description : A loud buzzing noise in an AC controller is probably caused by _____________. A. poor contact with the overload relay B. an incorrectly sized heater C. a broken shading coil D. abnormal starting current
Description : Basically, a magnetic amplifier is a saturable reactor with the addition of _____________. A. AC to the bias winding B. variable capacitance to all windings C. eddy current protectors D. a rectifier in the load circuit
Description : Across-the-line starters are used with AC motors to provide _____________. A. reduced starting current B. regulated starting current C. high starting torque D. controlled starting acceleration
Description : Shading coils are installed on AC full-voltage starters to _____________. A. eliminate contact chatter B. dissipate opening contact arcs C. delay current build up in the holding coil D. protect the motor windings from momentary starting current overload
Description : The purpose of DC generator brushes is to _____________. A. neutralize armature reaction B. conduct electric current to an outside circuit C. convert DC current to AC current D. provide excitation to a DC generator
Description : What.. so what is 1000 divided by 4.016?
Last Answer : 249.00398406375
Description : What will be the volume of CO2 at NTP obtained on heating 10 grams of (90% pure) limestone [Pb. CET 2001] (A) 22.4 litre (B) 2.016 litre (C) 2.24 litre (D) 20.16 litre
Last Answer : (B) 2.016 litre
Description : The amount of voltage induced in the windings of an AC generator depends mainly on _____________. A. the number of field poles energized B. the speed at which the stator windings rotate through the magnetic field C. the strength of the magnetic field D. all of the above
Description : How many revolutions will a turntable that rotates through an angle of 3 over 2 pi in one second make in 60 seconds?
Last Answer : I guess you mean 3 pi over 2, ie 3Ï€/2 though it may have been given to you as (3/2)Ï€ To solve this, find the total angle turned in 60 seconds and divide by the angle in a whole ... radians = 90Ï€/2Ï€ revolutions = 45 revolutions (45 rpm - the figure calculated - was the standard for a single).
Description : A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter by design, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz supply ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : A handheld digital tachometer could give a bad reading if ___________________. A. aimed directly at the shaft B. partially aimed at a 60 Hz. fluorescent light C. positioned 5-10 inches from the shaft D. the tape is too shiny
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration were in 180 degree error with those of the transmitter, what corrective action should be taken? EL-0092 A. Reverse the 60 Hz ... is proper operation. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration were in 180 degree error with respect to that of the transmitter, what corrective action should be taken? EL-0092 A. No action is ... and 'R2'. C. Interchange connections 'S1' and 'S2'. D. Interchange connections 'S1' and 'S3'.
Description : If coils 'R1-R2-R3' at the receiver of figure 'B' shown in the illustration turned opposite of those in the transmitter, what corrective action should be taken to have both turn in the same direction? EL-0092 A ... is needed. C. Interchange leads 'R1' and 'R3'. D. Interchange leads 'R2' and 'R3'.
Description : If coil 'R1-R2' at the receiver of figure 'A' shown in the illustration turned opposite of that in the transmitter, what corrective action should be taken? EL-0092 A. No action is necessary as this is ... . C. Interchange connections to 'S1' and 'S2'. D. Interchange connections to 'S1' and 'S3'.
Description : Assuming a standard 60 Hz. input to the circuit shown in the illustration, the ripple frequency would be ____________. EL-0085 A. 30 Hz B. 60 Hz C. 90 Hz D. 120 Hz