Description : What is the frequency of the output voltage of an alternator with four poles that is rotated at 3600 rpm?
Last Answer : 120 Hz.
Description : What two factors determine the frequency of the output voltage of an alternator?
Last Answer : Speed of rotation and number of poles.
Description : In an alternator at lagging power factor the generated voltage per phase as compared to that at unity power factor?
Last Answer : In an alternator, at lagging power factor the generated voltage per phase as compared to that at unity power factor must be more than terminal voltage.
Description : In a three-phase alternator, what is the phase relationship between the individual output voltages?
Last Answer : Each phase is displaced 120º from the other two
Description : How many voltage outputs are available from a two-phase three-wire alternator?
Last Answer : Three.
Description : A change in field excitation of an alternator operating in parallel will cause a change in its _____________. A. alternator frequency B. kilowatt load C. voltage output D. all of the above
Last Answer : Answer: C
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
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
Last Answer : Answer: D
Description : The frequency of an alternator at a given RPM is determined by the _____________. A. number of turns of wire in the armature coil B. number of magnetic poles C. strength of the magnets used D. output voltage
Last Answer : Answer: B
Description : The output voltage of a three-phase alternator is regulated by the _____________. A. AC voltage to the armature B. AC voltage to the field C. DC voltage to the armature D. DC voltage to the field
Description : The frequency output of an operating alternator is controlled by the _____________. A. relative speed of the rotor poles B. number of turns of wire in the armature coil C. strength of the magnets used D. output voltage
Last Answer : Answer: A
Description : One factor that determines the frequency of an alternator is the ____________. A. number of turns of wire in the armature coil B. number of magnetic poles C. strength of the magnets used D. output 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 : What are the two methods of connecting the outputs from a three-phase alternator to the load?
Last Answer : Wye and Delta.
Description : What type of prime mover requires a specially designed high-speed alternator?
Last Answer : Steam turbine.
Description : What is the main advantage of the rotating field alternator?
Last Answer : Output voltage is taken directly from the armature (not through brushes or slip rings).
Description : If a voltage (positive or negative) is measured on the "1" output of a flip-flop, what state is it in?
Last Answer : SET state.
Description : What would be the output of a negative clamper with a bias potential of −5 volts and an input voltage swing from +50 to −50 volts?
Last Answer : -5 volts.
Description : What is the output voltage of a CT when it is set on electrical zero?
Last Answer : Zero or minimum voltage.
Description : In a full-wave voltage doubler, are the capacitors connected in series or in parallel with the output load?
Last Answer : In parallel.
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease (which one) in the resistance of the regulating device.
Last Answer : An increase.
Description : The purpose of a voltage regulator is to provide an output voltage with little or no __
Last Answer : Variation.
Description : Does a filter circuit increase or decrease the average output voltage?
Last Answer : A filter circuit increases the average output voltage
Description : What is the average voltage (Eavg) Output of a full-wave rectifier with an output of 100 volts peak?
Last Answer : 63.7 volts.
Description : If the output of a half-wave rectifier is 50-volts peak, what is the average voltage
Last Answer : 15.9 volts.
Description : When the input and output wipers of a balanced potentiometer are in the same angular position, what is the value of the error voltage?
Last Answer : Zero.
Description : What characteristic is determined by the time required for a voltage wave to travel from the input end of an artificial transmission line to the output end and back again?
Last Answer : Pulse width
Last Answer : Pulse width.
Description : The purpose of a voltage regulator is to provide an output voltage with little or no _
Description : What two factors can cause output dc voltage to change?
Last Answer : Ac line voltage and a change in load resistance.
Description : If the inductance of a choke-input filter is increased, will the output ripple voltage amplitude (Er) increase or decrease?
Last Answer : Decrease.
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease in the resistance of the regulating device.
Last Answer : Increase.
Description : What is the average voltage (Eavg) output of a full-wave rectifier that has an output of 100 volts peak?
Last Answer : 63.6 volts.
Description : Why does using ac vice dc bias voltage result in a stronger output signal?
Last Answer : Because an ac bias voltage of the proper frequency and level places the input signal away from both steps in the magnetism curve. The result is two undistorted output signals that are combined into one strong output.
Description : What component causes a generator to produce dc voltage rather than ac voltage at its output terminals?
Last Answer : A commutator
Description : In signal generators, what device is used to regulate the voltage of the output signal?
Last Answer : Attenuator.
Description : What is the mathematical formula for computing the output voltage from a moving coil in a magnetic field?
Last Answer : 8. e = Emax sine θ.
Description : How is output voltage controlled in practical alternators?
Last Answer : By varying the voltage applied to the field windings.
Description : The variation in output voltage as the load changes is referred to as what? How is it expressed?
Last Answer : Voltage regulation. As a percentage.
Description : What is the name of the emf generated in the primary that opposes the flow of current in the primary?
Last Answer : . Self-induced or counter emf
Description : What are three ways of controlling the amount of transmitter-generated emi?
Last Answer : (a) filtering and shielding of the transmitter (b) limiting bandwidth (c) cutting the antenna to the
Description : An emf is generated in a conductor when the conductor is cut by what type of field?
Last Answer : Magnetic field.
Description : What condition produces the 10-kHz error signal generated by the metering bridge in the HP- 431C power meter?
Last Answer : An unbalance in the metering bridge.
Description : Motorization of an alternator is undesirable because _____________. A. the alternator will be damaged B. it puts an additional load on the bus C. high voltage pulses are induced in the bus D. all of the above
Description : Which of the following actions must be carried out prior to closing the alternator circuit breaker according to the graph shown in the illustration? EL-0002 A. Increase the alternator voltage. B. Decrease the line voltage. C. Increase the line voltage. D. Decrease the line frequency.
Description : An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. ... of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage
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 : To remove an alternator operating in parallel with another unit from the main electrical bus, you must FIRST _________. A. adjust the power factor on both units B. set the desired voltage on ... C. open the circuit breaker on the outgoing alternator D. remove the load from the outgoing alternator
Description : If field excitation is suddenly lost to an alternator operating in parallel, that alternator will _____________. A. supply excessive current to the bus B. operate at the same load, but with reduced voltage C. lose its load and tend to overspeed D. become overloaded and slow down