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
Last Answer : Answer: D
Description : The Wheatstone bridge is a precision measuring instrument utilizing the principle of changes in _____________. A. inductance B. capacitance C. resistance D. amperage
Last Answer : Answer: C
Description : Over lap Angle depends on_________ a) Load inductance b) Loa capacitance c) Source inductance d) Source capacitance
Last Answer : Ans: Source inductance
Description : A saturable-core reactor operates on the principle of controlling a load winding's inductance by varying the core's _____________. A. dielectric B. permeability C. reactance D. inductance
Last Answer : Answer: B
Description : The formula for computing impedance in a series circuit containing resistance, capacitance, and inductance is _____________. [ NOTE: the symbol * stands for 'multiplied by' ] A. Z = RT + XL + XC B. Z = R + XL - XC C. Z * Z = R * R + (XL - XC) * (XL - XC) D. Z = R * R + (XL * XC) - (XL * XC)
Description : Capacitance is the property of an electric circuit opposing a change in the _____________. A. current in the circuit B. voltage in the circuit C. inductance in the circuit D. resistance in the circuit
Description : AC circuits develop resistance, inductance, and capacitance. The inductive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads
Last Answer : Answer: A
Description : Alternating current circuits develop resistance, inductance, and capacitance. The capacitance of individual capacitors is expressed in _____________. A. ohms B. mhos C. henrys D. farads
Description : Alternating current circuits develop resistance, inductance and capacitance. The inductance of a coil is expressed in _____________. A. ohms B. mhos C. henrys D. farads
Description : AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads
Description : The resistance in a magnetic material is called as a) Capacitance b) Inductance c) Reluctance d) Magnetic resistance
Last Answer : c) Reluctance
Description : Inductance is the property of an electric circuit that _____________. A. opposes any change in the applied voltage B. opposes any change in the current flow through the circuit C. aids any changes in the applied voltage D. aids any changes in the current through the circuit
Description : The value of the capacitance depends upon the________________? A.voltage applied B. thickness of the capacitor plates C. geometry of the capacitor D. dinsity of the capacitor plates
Last Answer : Ans: C
Description : Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. ... . D. Total opposition to the flow of alternating current depends upon the amount of reactive power.
Description : The mutual inductance of the coil depends upon: a. density of the coil b. stiffness of coil c. material of coil d. geometry of the coil
Last Answer : d. geometry of the coil
Description : Basic electrical motor action depends on _______________. A. a conductor rotated within a magnetic field B. a current carrying conductor placed in a magnetic field C. the relative force of the commutator and commutating poles D. the relative force of the armature and interpoles
Description : .A(75-j50)-is connectedtoa coaxialtransmission lineofZO=75 ,at 10GHz.The bestmethod ofmatching consistsin connecting a. a short-circuited stub at the load b. an inductance at the load c. a capacitance at some specific distance d. a short-circuited stub at some specific distance from the load
Last Answer : d. a short-circuited stub at some specific distance from the load
Description : An operational amplifier, as used in today's consoles, has a calculated gain of 5. This means that when the input changes _____________. A. 5 volts, the output changes 10 volts B. 10 volts, the output changes 5 volts C. 2 volts, the output changes 10 volts D. 10 volts, the output changes 2 volts
Description : Figure 'B' shown in the illustration represents a/an ____________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid
Description : Figure 'A' shown in the illustration represents a/an _______________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid
Description : An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a ____________. A. magnetic amplifier B. ship's service alternator C. three-wire DC generator D. saturable core reactor
Description : In the construction of D.C. motors, parts of both the series and shunt fields are wound on the _____________. A. opposite main pole B. rotor core C. interpole D. same main pole
Description : Hays bridge is used to measure___________ and Schering bridge is used to measure____________ a) Inductance, Inductance b) Inductance, Capacitance c) Capacitance, Inductance d) Resistance, Capacitance
Last Answer : Ans: Inductance, Capacitance
Description : In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator
Description : The diagram shown in the illustration represents a/an _____________. EL-0082 A. stepup transformer B. magnetic amplifier C. autotransformer D. Scott-connected transformer
Description : Basic operating characteristics of the operational amplifier such as gain and stability are the function of its _____________. A. differential input stage B. power output stage C. feedback circuit D. supply voltages
Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity
Last Answer : B. Velocity factor
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 : The governor control switch of an alternator is moved to the 'raise' position. This action will _____________. A. raise the no-load speed setting of the governor B. raise the percentage of speed droop C. lower the no-load speed setting of the governor D. lower the percentage of speed droop
Description : In the illustrated circuit, one advantage of the capacitor coupling over direct coupling is ____________. EL-0048 A. as the frequency decreased the capacitive reactance (Xc) increases B. the amplifier becomes ... of the signal while it isolates the biasing of each stage. D. good frequency response.
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 : In the illustrated electronic governor, the circuit card connected to the potential and current transformers is for ________. EL-0046 A. increasing the signal strength to the governor to ... from motorization D. conditioning the load through the use of a magnetic amplifier current transformer
Description : The conversion of the throttle command voltage to the signal necessary to achieve the desired shaft RPM is accomplished by the _____________. A. ahead or astern function generator of the ... circuit C. operational amplifiers in the autorotation circuit D. long time constant amplifier circuit
Description : The set point current at which a magnetic-type overload relay tends to trip may be increased by turning the dashpot in the 'lower' direction. This action _____________. A. reduces magnetic force on ... the relay D. increases magnetic force on the plunger and requires less current to trip the relay
Description : An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected
Description : The true power indicated by a wattmeter depends on the current flow through the load, the magnitude of the potential across the load, and the _____________. A. power factor of the load B. angle of coil displacement C. inertia of the movable coil D. high resistance from the load
Description : Explain on the material used for core construction?
Last Answer : A:The core is constructed by sheet steel laminations assembled to provide a continuous magnetic path with minimum of air gap included. The steel used is of high ... The thickness of lamination varies from 0.35mm for a frequency of 50Hz and 0.5mm for a frequency of 25Hz.
Description : Brush sparking during commutation may be caused by ________. A. eddy currents in the armature core B. laminations in the generator field pieces C. induced current opposite to coil inductance D. coil inductance discharge occurring at commutation
Description : State the effects of errors in dynamometer type wattmeter due to i) pc- inductance ii) pc- capacitance iii) mutual inductance iv) Connection.
Last Answer : Errors in wattmeter: i) pc - inductance: Pressure coil inductance causes wattmeter to read more power than actual . ii) pc-capacitance: The wattmeter reads less power. iii) ... iv) Connection: In uncompensated wattmeter , the reading of wattmeter includes the powerloss in coils.
Description : When a megohmmeter is used to test the dielectric strength of wire insulation, the initial dip of the pointer toward 'zero' is caused by _____________. A. good insulation B. the leakage of ... of dirty insulation C. the capacitance of the circuit D. the dielectric absorption effect of the insulation
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 : An AC circuit has capacitance arranged in series. If the line voltage remains constant, the capacitive reactance value can be varied by changing the _____________. A. line frequency B. resistance C. number of commutating poles D. number of interpoles
Description : On tank vessels with an electrically-driven capstan, the motor should be meggered periodically to test _____________. A. insulation resistance B. eddy currents C. capacitance D. armature reactance
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 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 : The inductance of a coil is measured in _____________. A. ohms B. volts C. henries D. amperes
Description : When troubleshooting a magnetic controller, it is found that the contacts are welded together. The most probable cause is _____________. A. excessive operation at low load B. high ambient temperature C. low voltage on the operating coil D. high voltage on the operating coil
Description : In the heating process of the ________type a simple method of temperature control is possible by means of a special alloy which loses its magnetic properties at a particular high temperature and regains ... ) core type induction furnace (C) coreless induction furnace (D) high frequency eddy current
Last Answer : Ans: D Magnetic property of alloy changes with change of the temperature and Heat is produced due to eddy current = i2R and i α f2
Description : The existing resistance of a conductor is dependent upon its length, cross-sectional area, _____________. A. temperature and insulation B. material and insulation C. resistive coefficient and material D. material and temperature
Description : As shown in the illustrations, ordered rudder angle is fed back from the ________________. EL-0097 A. power unit to the magnetic amplifier B. steering gear to the control potentiometer C. magnetic amplifier to the steering gear D. rudder yoke to the non-followup controller