Description : An accidental path of low resistance, allowing passage of abnormal amount of current is known as a/an ____________. A. open circuit B. short circuit C. polarized ground D. ground reference point
Last Answer : Answer: B
Description : When insulation failure produces a low resistance current path between two conductors, the resulting condition is known as ____________. A. an open B. a short circuit C. a ground D. a surge
Description : A current-carrying conductor makes accidental contact with a wiring conduit. This will be indicated by a _____________. A. low switchboard wattmeter reading B. high switchboard wattmeter reading C. darkened switchboard ground detecting lamp D. darkened switchboard synchronizing lamps
Last Answer : Answer: C
Description : With both ends of a three conductor cable disconnected and arranged without the conductors touching each other, an ohmmeter reading of 'zero' ohms between the ends of one conductor would indicate _____________. A. continuity B. a partial ground C. the resistance is infinite D. a short circuit
Last Answer : Answer: A
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
Last Answer : Answer: D
Description : Accidental grounds in a shipboard electrical system must be repaired as soon as possible as they will ____________. A. result in immediate power outages B. damage circuit breakers C. appear on the ground detection system D. damage insulation and may cause outages
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 : The winch shown in the illustration will not operate in any speed in the lowering direction and at an abnormal speed in 'first point hoist'. The possible cause is that _______________. EL-0102 A. ... '1M' in the power circuit are badly corroded D. master switch contacts 'MS6' have weak springs
Description : To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt
Description : A ground is indicated by the ground-detecting system on the main electrical switchboard. The FIRST step in locating the actual ground is to _____________. A. close all circuit breakers in ... ground detection system indicates normal C. change over generators D. check each circuit with a megohmmeter
Description : The ground indicating light on the main electrical switchboard is indicating a ground. The best procedure for locating the grounded circuit is to _____________. A. trace the circuit paths while looking for ... a time, until the lights no longer indicate a ground D. check all circuits for continuity
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 : 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 : A infinite resistance is considered as a/an a) Closed path(short circuit) b) Open path c) Not defined d) Ammeter with zero reading
Last Answer : b) Open path
Description : A circuit with a blown fuse would be described as a/an _____________. A. short circuit B. open circuit C. bonded circuit D. grounded circuit
Description : The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts by _____________. A. designing the contacts to open slowly B. directing the arc into an ... an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents
Description : Which of the following represents a characteristic of an ungrounded electrical distribution system? A. Accidental contact between one line and ground does not cause an outage. B. Double ground faults on ... unnecessary. D. Accidental contact between one line and ground will always cause an outage.
Description : In addition to short circuits and sustained overloads, fuses are likely to blow due to _____________. A. loose fuse clips B. low ambient temperatures C. low contact resistance D. all of the above
Description : A low-voltage protection circuit is used in electric motor starting equipment to _____________. A. trip circuit contactors when the motor overspeeds due to low voltage B. trip circuit ... voltage without manually resetting D. prevent the motor from restarting automatically on restoration of voltage
Description : To properly use a hook-on-type volt/ammeter to check current flow, you must FIRST _____________. A. de-energize the circuit to allow connection of the instrument in series B. hook the jaws ... test leads to the appropriate terminals D. short the test leads and calibrate the instrument to zero
Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency
Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the run winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency
Description : The main difference between a motor control circuit containing low voltage protection and low voltage release is that the latter contains _____________. A. a magnetic operating coil B. normally open line contacts C. thermal-overload protection D. a momentary-contact start button
Description : A current-carrying conductor making electrical contact with a wiring conduit will be indicated by a _____________. A. high switchboard wattmeter reading B. totally dark switchboard ground detecting light C. low switchboard wattmeter reading D. all of the above
Description : A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light
Description : When used for taking resistance measurements, a volt-ohm-milliammeter is normally powered by _____________. A. a hand cranked generator B. internal storage batteries C. the current in the circuit being tested D. a step down transformer
Description : When shipboard electrical distribution circuits are connected in parallel, additional parallel circuits will cause the total circuit resistance to _____________. A. increase, causing a drop in the line current B ... an increase in the line voltage D. decrease, causing an increase in the line current
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 : When the voltage remains constant, and the resistance increases in a series circuit, current flow _____________. A. decreases B. remains the same C. increases D. increases by the square
Description : When the voltage remains constant and the resistance is increased in a series circuit, the flow of current _____________. A. increases by the square of the original value B. increases C. remains the same D. decreases
Description : If the resistance of a circuit is cut in half and the applied voltage is kept constant, the current flow will be _____________. A. doubled B. quadrupled C. unchanged D. cut in half
Description : The total voltage of a series circuit is the _____________. A. sum of the individual voltage drops B. total resistance divided by the total current C. sum of the individual currents multiplied by the number of resistors D. total current divided by the total resistance
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 : A circuit breaker and a fuse have a basic similarity in that they both _____________. A. can be reset to energize the circuit B. should open the circuit when overloaded C. will burn out when an over current flow develops D. all of the above
Description : The component labeled 'CR1' in the circuit shown in the illustration __________________. EL-0085 A. varies its anode/cathode polarity depending on 'RL' current B. rectifies the varying voltage from the ... reactance to smooth ripple D. establishes a constant reference voltage for the base of 'Q1'
Description : In an alternating current electrical system, a low system power factor is a direct sign of _____________. A. wasted energy B. efficient operation C. a short in the exciter field windings D. an excessive number of minor system grounds
Description : The combined effect of inductive reactance, capacitive reactance, and resistance in an AC series circuit is known as _____________. A. reactance B. total reactance C. impedance D. resonance
Description : An electrical connection between the wiring of an electric motor and its metal frame is known as a/an _____________. A. eddy current B. ground C. impedance D. flux leakage
Description : The basic meter movement responds to the flow of current through its coil. Therefore, this meter movement may be used as a/an _____________. A. voltmeter by placing a resistance in parallel with the ... in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil
Description : A characteristic of an induction motor with a low resistance rotor winding is _____________. A. high starting voltage B. high starting current C. high slippage D. low starting voltage
Description : The potentiometers shown in the illustration are supplied with both (+) and (-) voltages as well as a reference to ground ________________. EL-0095 A. so there is always a spare power ... , the other for relay operation and the potentiometers are in positions where they can be accidentally touched
Description : In the illustration, the small battery and Rb are in the circuit to apply ________. EL-0022 A. forward bias to the emitter-base B. reverse bias to the emitter-base C. a 'reference charge' on the input capacitor D. a buffer between the input ground and the emitter ground
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 : A flickering ground detection lamp on a DC system would indicate a _____________. A. multiple-ground condition in the distribution system B. ground in an armature coil of an operating machine C. ground in a motor accompanied with a short D. short between two adjacent bars of the generator commutator
Description : Any electric motor can be constructed to be _____________. A. short proof B. ground proof C. explosion proof D. overload proof
Description : In preparing to take insulation resistance readings on a main generator, the windings should be grounded for about 15 minutes prior to the test to _____________. A. allow accurate zeroing of the meter ... the windings D. help the windings to cool to the same temperature as the ground test connection
Description : Multiple grounds have developed and were initialy indicated by the grounddetecting system as one ground. The FIRST step in locating the grounds is to _____________. A. examine the main bus bars ... no longer indicates any grounds C. change over generators D. check each circuit with a megohmmeter
Description : A ground in an electrical circuit outside the engine room _____________. A. cannot be detected under normal conditions B. is of no consequence to engineering personnel C. is indicated at the branch circuit breaker panel D. is indicated by the ground detecting lamps on the main switchboard
Description : When using an ohmmeter to test a semiconductor diode, you find a low resistance in both the forward and reverse bias directions. This indicates that the diode has a/an ____________. A. open B. short C. good resistive quality D. good capacitive quality
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