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Master Closed Book Exam questions and accurate answers # A grounding conductor installed over lighting cables for the purpose of interconnecting the system ground electrodes and providing lighting protection for the cables is called a/an ________. a) air terminal b) ground anchor c) counterpoise d) grounding connector rod - c) counterpoise A surge of unidirectional polarity is called __________. a) corona b) flashover c) skin effect d) impulse - d) impulse The minimum temperature at which a given liquid gives off vapor in sufficient concentration to form an ignitable mixture is the ____________. a) absolute temperature b) kindling temperature c) flash point d) heat of fusion - c) flash point Emergency power panel conductors supplying a building are tapped on ____________. a) any subbed panel
b) any circuit breaker main c) any feeder circuit d) the line side of the service - d) the line side of the service The grounding electrode conductor shall be _______. a) copper b) copper-clad aluminium c) aluminium d) any of these - d) any of these A ___________is usually made on cables after installation. a) ampacity test b) no-load test c) copper loss test d) insulation resistance test - insulation resistance test When you increase the resistance in a circuit, the flow of electrons will __________. a) flow faster b) be stopped c) be decreased d) be constant - c) be decreased An instrument used for observing voltage or current waveforms is the ___________. a) synchroscope
a) it adequately insures the safety of the user b) its value is mainly to the untrained electrician helper c) the insulation provides very little real protection d) the insulation should not be used as the only protection means - d) the insulation should not be used as the only protection means A transformer has a turns ratio of 4/1. What is the secondary peak voltage if the primary has an applied voltage of 115? a) 40. b) 81. c) 162. d) 28.75 - a) 40. If the power factor of a circuit is unity, its reactive power is _________. a) zero b) a maximum c) equal to PR d) a negative quality - a) zero A/an ______ has the least number of electrons. a) semiconductor b) conductor c) insulator d) none of these - b) conductor A/ an _________ is used to maintain the strength of a magnetic field.
a) keeper b) air gap c) container d) gauser - a) keeper If a transformer bank is using an open delta connection, _________ single-phase transformers are interconnected. a) three b) only one c) two d) two primary and one secondary - c) two Which of the following raceways in NOT permitted to be used in a hazardous location? a) Liquidtight flexible metal conduit b) Rigid non-metallic conduit c) Rigid metal conduit d) None of these - b) Rigid non-metallic conduit A contact connected in a control circuit that will ensure that a particular sequence of operation is followed is called a/an ___________. a) seal-in b) interlock c) overlatch d) bonding jumper - b) interlock
Which of the follow posses four valence electrons? a) Insulators b) Semiconductors c) Semi-insulators d) Conductors - b) Semiconductors The capacitor opposes any change in voltage across it by ___________. a) acting as a short circuit at time equal to infinity b) acting as a short circuit at time equal to zero c) passing a voltage proportional to the rate of change of current d) passing a current proportional to the rate of change of voltage - d) passing a current proportional to the rate of change of voltage The force which sets up or tends to set up magnetic flux in a magnet is ________ force. a) electromotive b) magnetomotive c) dynamic d) potential - b) magnetomotive During the short circuit test on a transformer, _________ is shorted. a) both sides b) either side c) low side
d) high side - c) low side In a given circuit, when the power factor is unity, the reactive voltamps are ________. a) zero b) maximum c) equal to the current d) equal to the apparent power - a) zero A diagram showing the physical location of coils, contracts, motors and the like in their actual positions would be a ________ diagram. a) schematic b) power flow c) ladder d) wiring - d) wiring The power factor of a certain circuit in which the voltage lags behind the current is 80%. To increase the power to 100%, it is necessary to add ________ to the circuit. a) resistance b) capacitance c) inductance d) impedance - c) inductance The reciprocal of capRcitance is called____________. a) elastance b) permeability
b) clipping c) reversing d) inching - d) inching The period of an AC wave is _______. a) the ratio of amplitude to the frequency b) the same as the frequency c) the reciprocal of frequency d) not related to frequency - c) the reciprocal of frequency The Kva rating of an ordinary two winding transformer is increased when connected as an autotransformer because __________. a) the secondary voltage is increased b) the secondary current is increased c) transformation ratio and is increased d) energy is transferred both inductively and conductively. - d) energy is transferred both inductively and conductively. If the resistance in a circuit is increased, the flow of electrons will _____. a) be stopped b) be decreased c) be faster d) be multiplied - b) be decreased The peak value of an AC sine wave is the same as the _________.
a) effective value b) rms value c) instantaneous value d) maximum value - d) maximum value A megger is connected to the ends of a motor winding. A low ohm reading indicates ________. a) open coil b) continuity c) loose coil d) dirty coil - b) continuity After the starting winding of a single-phase induction motor is disconnected from supply, it continues to run only _______ winding. a) field b) rotor c) compensating d) stator - b) rotor An electrical temperature sensing device which is composed of a pair of different kinds of metal wires joined together in three complete loops is a _______. a) flowmeter b) psychrometer c) thermocouple d) photoconductive cell - c) thermocouple
An assembly of two pieces of insulating material provided with grooves for holding one or more conductors at a definite spacing from the surface wired over and from each other, and with holes for fastening in position is a __________. a) cleat b) spool insulator c) split knob d) rosette - a) cleat The disadvantage of a mechanical switch is that it ________. a) is costly b) is operated mechanically c) has high inertia d) has a lower corona - c) has high inertia Suppose the primary line voltage fluxuates between 105 and 125 volts on a 5/1 step down transformer. The maximum secondary peak voltage would be approximately a) 88 b) 18 c) 74 d) 35 - d) 35 The force between tow electrically charged objects is called _______. a) electroscopic force b) magnetic force
c) eddy currents d) electrostatic force - d) electrostatic force
