Description : Which of the terms listed best describes a compound-wound DC generator having a higher voltage at no load than at full load? A. Flat compounded B. Over compounded C. Under compounded D. Terminal compounded
Last Answer : Answer: C
Description : Which of the following statements is true about the illustrated circuit? EL-0030 A. The field rheostat is used for manual voltage control. B. if the generator is flat compounded then the field rheostat ... to act like a series motor and overspeed with the controller in the full raise position.
Last Answer : Answer: A
Last Answer : In over compounded generator, full load terminal voltage is more than no load terminal voltage.
Description : The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. ... in series with the load D. balance coil diverting neutral current through the shunt field
Last Answer : In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.
Description : A three-phase alternator is operating at 450 volts, 250 amps at 0.6 power factor. If the power factor increases to 0.8, the kw load potential will increase by _____________. A. 38.525 kw B. 116.91 kw C. 155.88 kw D. 194.85 kw
Description : In a three-wire, 230/115 volt DC system, the potential between neutral and negative is _____________. A. 0 volts B. 115 volts C. 230 volts D. 460 volts
Last Answer : Answer: B
Description : The electrical diagram shown in the illustration represents a ___________. EL-0054 A. series-wound motor B. shunt-wound motor C. compound-wound motor D. flat-compounded motor
Description : The distance between a generator and its load is 100 feet. What would be the approximate total voltage drop across a two wire supply cable if the current were 5.5 amperes and the resistance of the wire were 2.525 ohms per 1,000 feet? A. 0.5 volts B. 1.38 volts C. 1.90 volts D. 2.77 volts
Last Answer : Answer: D
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 : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.
Last Answer : (C) less than 800 rpm.
Last Answer : In case of a flat compounded generator voltage remains constant irrespective of the load.
Description : Hysteresis in a direct current generator is indicated by _____________. A. arcing at the brushes B. pulsating terminal current C. heating of the armature core D. hunting and over control
Description : The kilowatt load can be adjusted on a paralleled generator by using the _____________. A. field rheostat B. governor control C. automatic voltage regulators D. hand tachometer
Description : The most practical way to control the voltage output of an AC generator is to vary the _____________. A. number of windings B. speed of the rotating field C. strength of the rotating magnetic field D. power factor of the load
Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators
Description : The power factor at which a paralleled AC generator operates is usually adjusted by the _____________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage
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 : In the illustration, the component VR2 on the A1 AMPLIFIER MODULE is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply from common B. a variable resistor diode to control the output to terminal ... 2 at 9.1 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Description : In the illustration, the component VR1 on the A1 AMPLIFIER MODULE is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply from common B. a variable resistor diode to control the output to ... terminal 9 at 6.6 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Description : In the illustration, the component VR1 on the A1A1 PCB is _________. EL-0060 A. a zener diode to regulate the +9 volt power supply B. a variable resistor diode to control the output to terminal 9 that controls ... terminal 9 at 6.6 volts DC D. a tunnel diode with a breakdown voltage of 6.6 Volts DC
Description : In the illustrated circuit, what is the voltage of the battery if the resistance of R1 is 150 ohms, the total resistance is 250 ohms and the current though R2 is 25 milliamps? EL-0036 A. 12 volts B. 24 volts C. 1.5 volts D. 6.25 volts
Description : A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________. A. check for shorted coils with a growler B. take moisture readings with a ... a megger D. ground the commutator, or slip rings and run it at half load for 12 hours
Description : if voltage is 230 Volts , frequency is 50 Hz and current is 1 ampere then what will be the resistance?
Last Answer : As V = 230v and I = 1A Therfore by ohm's law V =IR R = V/I =230/1 =230 ohm
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 : An emergency generator, driven by an internal combustion engine, shall be tested under load for a minimum of 2 hours at least once every _____________. A. week B. 2 weeks C. month D. 3 months
Description : The open-circuit voltage of a fully charged lead-acid battery cell is _____________. A. 1.5 volts B. 1.8 volts C. 2.0 volts D. 2.3 volts
Description : A lead-acid battery is considered fully charged when the ______________. A. electrolyte gasses freely B. battery charger ammeter indicates a positive reading C. terminal voltage reaches a constant value at a ... cells reaches the correct value and no longer increases over a period of 1 to 4 hours
Description : A lead-acid battery cell sustaining a short circuit _______. A. will be indicated by lime accumulation on the terminal posts B. will have unusually high cell voltage C. will become excessively heated while being charged D. cannot be completely discharged under load
Description : Which of the following actions must be carried out before a voltage tester can be used to test the three line fuses to a three-phase motor? A. The fuses must be removed from the circuit. B. The ... disconnected and tagged. D. Nothing need be done as long as the motor is running under a light load.
Description : The terminal voltage of a DC shunt generator drops on load because of all of the following except : (A) Armature reaction (B) Armature resistance drop (C) Commutation (D) Field weakening due to armature reaction and armature resistance drop
Last Answer : (D) Field weakening due to armature reaction and armature resistance drop
Description : An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from ... C. any suitable ground to any available line lead D. any field pole to each field coil lead
Description : When paralleling two alternators using three synchronizing lamps, the flickering of all three lamps becomes progressively slower and slower. This means the ______________. A. frequency of the incoming ... the bus D. terminal voltage of the incoming alternator is approaching that of the bus
Description : What are the factors, which varies terminal voltage of generator?
Last Answer : a) Voltage drop due to resistance (Ra drop). This is negligible. b) Voltage drops due to leakage reactance (XL). c) Voltage drops due to armature reaction.
Description : A dc cumulatively compounded motor delivers rated load torque at rated speed. If series field is short circuited, then the armature current and speed will a) Both increases b) Both decreases c) Increases and decreases d) Decreases and increases
Last Answer : Ans: Both increases
Description : An Alternator is found to have its terminal voltage on load condition more than that on no load. What is the nature of the load connected?
Last Answer : The nature of the load is of leading power factor , load consisting of resistance and capacitive reactance.
Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L5? [ NOTE: Kirchhoff's voltage and current laws apply ] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts
Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L1? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.3 volts D. 114.8 volts
Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L2? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts
Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L3? [NOTE: Kirchhoff's voltage and current laws apply.] EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts
Description : If the total source voltage of the three-wire distribution system shown in the illustration is 240 volts, what is the voltage across load L4? EL-0075 A. 110.4 volts B. 112.2 volts C. 113.0 volts D. 114.8 volts
Description : What is the load voltage 'Es' as shown in the illustration? EL-0083 A. 292 volts B. 360 volts C. 450 volts D. 810 volts
Description : An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically ... the series field of the incoming generator D. parallel the series fields of the generators
Description : A variable shunt, connected across the series field coils of a DC compound wound generator, to permit adjustment of the degree of compounding, is called a _____________. A. divider B. diverter C. converter D. rheostat
Description : Moving the rheostat handle shown in the illustration, that is used to control a DC generator, towards the 'raise' direction will increase the _____________. EL-0030 A. field resistance B. armature resistance C. armature speed D. line voltage
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 : An alternator will fail to produce line voltage as a result of _____________. A. a closed circuit breaker B. oxidized slip rings C. improperly staggered brushes D. exciter generator failure
Description : DC generator voltage is decreased by cutting _____________. A. in field resistance B. out field resistance C. in armature resistance D. out armature resistance
Description : The voltage of an operating AC turbogenerator is raised or lowered by adjusting the _____________. A. exciter generator governor controls B. synchronizing switch C. phase sequence switch D. generator field exciter
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