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 different phases will not cause an outage. C. Ground detection systems are unnecessary. D. Accidental contact between one line and ground will always cause an outage.  

1 Answer

Answer :

Answer: A

Related questions

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

Last Answer : Answer: D

Description : Ungrounded neutral transmission system is not recommended because of system (a) insulation being overstressed due to over voltages (b) insulation overstress may lead to failure and subsequent phase to phase faults (c) being inadequately protected against ground fault (d) all of the above

Last Answer : (d) all of the above

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

Last Answer : Answer: B

Description : If all of the ground detection lamps burn with equal brilliance, whether the test button is depressed or released, then ___________. A. no grounds exist B. all phases are grounded C. all lamps show a ground D. all of the above

Last Answer : Answer: A

Description : If all three ground-detection lamps continue to burn at equal intensity after the test button is depressed and released, which of the listed conditions is indicated? A. No grounds exist B. All three phases are grounded C. The test switch is faulty D. The current transformers are shorted out

Last Answer : Answer: A

Description : On a switchboard, if all three ground detection lamps remain burning at half intensity when the test button is depressed, which of the listed conditions is indicated? A. No grounds exist. B. All three phases are grounded. C. The test switch is grounded. D. The current transformers are shorted.

Last Answer : Answer: A

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 : A three-phase electrical system is equipped with ground detecting lamps. If one of the lamp goes dark and the other two burn normally before and after the test switch is operated, this indicates _______________. ... of the three phases D. the voltage to the dark lamp is less than that of the system

Last Answer : Answer: A

Description : Which of the following statements is correct concerning the circuits in a sound powered telephone system? A. The ringing circuit is composed of only one common wire to ground. B. The common ... connected to each station. D. The talking and calling circuits are electrically dependent upon each other.

Last Answer : Answer: B

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

Last Answer : Answer: B

Description : If the illustrated motor fails to start and gives a loud hum when the start button is pushed, the problem is ________. EL-0007 A. one of the phases to the motor is not energized because of ... electrical distribution system D. 'OL1' is open because of 'T1' overload causing the motor to single phase

Last Answer : Answer: A

Description : The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist positions. Which of the listed faults ... '2M' in the power circuit may be badly corroded. D. Series relay 'FR' may be open.

Last Answer : Answer: A

Description : In a three-phase electrical system, three ground detecting lamps are provided. If all three lamps REMAIN at half-brilliance when the ground detecting test switch is operated, ______________. A. there is a ... must be replaced C. there are no grounds present D. the light bulbs are of improper voltage

Last Answer : Answer: C

Description : Which of the following statements is true regarding the illustrated circuit? El-0069 A. This full wave bridge should never be used aboard ship because the ground on lead 'A' will show on ... be direct current suitable for electronic circuits requiring voltage regulation. D. All the above are true.

Last Answer : Answer: B

Description : When a transmission line uses ground return, it is called a/an __________ line. A. ungrounded B. balanced C. unbalanced D. grounded

Last Answer : C. unbalanced

Description : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then  (A) zero sequence currents are present on both sides of the transformer  (B) ... side  (D) zero sequence currents are present on the primary side but not on the secondary side

Last Answer : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then zero sequence currents are absent on both sides of the transformer 

Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.

Last Answer : Answer: A

Description : The ground detection system, shown in the illustration for a low-voltage, threephase system has a ground in line 'A'. Therefore, lamp 'A' will burn ____________. EL-0009 A. dimly or be out, and lamps 'B' and ... and 'C' will burn dimly or be out D. brightly, and lamps 'B' and 'C' will burn normally

Last Answer : Answer: A

Description : An accidental path of low resistance which passes an abnormal amount of current is known as a/an _____________. A. polarized ground B. short circuit C. ground reference point D. open circuit

Last Answer : Answer: B

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 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

Last Answer : Answer: D

Description : As shown in the illustration, which of the symbols represents a normally closed electrical contact? EL-0005 A. A B. B C. C D. D

Last Answer : Answer: A

Description : Which of the following statements represents the FIRST precaution to be taken prior to working on any installed electrical component? A. Wear rubber gloves and boots. B. Use only approved nonconducting ... the machine before beginning any repairs. D. Open the supply circuits and tag the switches.

Last Answer : Answer: D

Description : Sparking of D.C. motor brushes can be caused by __________. A. an open commutating winding B. many mechanical, electrical or operating faults C. an open interpole D. all of the above

Last Answer : Answer: B

Description : Why ungrounded 250V DC system adopted in our system?

Last Answer : The 250V DC system is feeding to some of the vital loads such as breaker control etc. Even if one ground has occurred then also these controls should be available. Continuous monitoring of ground current is employed to eliminate the by passing of logic due to double ground. 

Description : What are the advantages of ungrounded system?

Last Answer : Supply is maintained even with fault on one line Less interference to communication lines because of absence of zero sequence currents.

Description : An ungrounded antenna near the ground A. acts as a single antenna of twice the height B. is unlikely to need an earth mat C. acts as antenna array D. must be horizontally polarized

Last Answer : C. acts as antenna array

Description : Most shipboard distribution systems use ac power that has what number of phases?

Last Answer : Three.

Description : A breakable, mercury-filled thermometer should not be used in a lead-acid battery to measure electrolyte temperature, as an accidental breakage can cause ____________. A. severe sparking and explosions ... battery plates C. violent gassing at the positive plates D. corrosion on the battery terminals

Last Answer : Answer: A

Description : Mercury filled thermometers should never be used to determine the temperature of the battery electrolyte because accidental breakage of the thermometer can cause __________________. A. severe sparking and ... of battery plates C. contamination of the electrolyte D. corrosion on the battery terminals

Last Answer : Answer: A

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

Last Answer : Answer: B

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

Last Answer : Answer: D

Description : In the illustrated ground detection system with a ground on phase A, if the switch is opened __________. EL-0009 A. lamp A will dim or go out depending on the severity of the ground B. all three ... lamp A will be brighter D. lamp A will start flickering if the ground is in an AC induction motor

Last Answer : Answer: B

Description : The circuit illustrated represents a single phase AC ground detecting system. If a ground occurs on line 'B', which of the lamps will burn the brightest? EL-0008 A. X B. Y C. Both will be equal brightness. D. both will go out.

Last Answer : Answer: A

Description : Levi Strauss markets its blue jeans in many countries, developing its marketing strategy as if the world is a single entity. This approach to selling a standardised product in many ... of international marketing? A)Exporting B)Accidental exporting C)International exporting D)Global marketing

Last Answer : D)Global marketing

Description : The severity of line to ground and three phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu, Z1=Z2=j0.1 p.u. and Z0= j0.05 p.u. for the alternator, then the required inductive ... a) 0.05 p.u. (b) 0.0166 p.u. (c) 0.1 p.u. (d) 0.15 p.u.

Last Answer : The severity of line to ground and three phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu, Z1=Z2=j0.1 p.u. and Z0= j0.05 p.u. for the alternator, then the required inductive reactance for neutral grounding is 0.0166 p.u.

Description : To determine if a stator coil is grounded, you should use a/an _____________. A. ammeter B. ground detection lamp C. magneto D. megger

Last Answer : Answer: D

Description : The electrical schematic shown in the illustration represents a/an ____________. EL-0017 A. across-the-line starter B. primary-resistor starter C. autotransformer starter D. part-winding starter

Last Answer : Answer: A

Description : I have a Surge Protector (with Data Line protection: ethernet, telephone, coaxial cable) Plugged into a UNGROUNDED Outlet. Do is there a risk? It is Safe?

Last Answer : My understanding is that the surge protector helps keep your equipment safe. And the grounding helps keep you safe. The surge protector will trip a circuit so any power spikes won't damage your stuff that is ... least that is how my brother in law explained it to me. (he is a licensed electrician)

Description : Write the safety measure in the following accidental cases: (i) Eye injury (chemical) (ii) Burn (iii) Skin contact (iv) Inhalation of toxic fumes.

Last Answer : Safety measures for: i)Eye injury : a) Have the person immediately rinse the eye with clean water. b) Flush with lukewarm water for 15-30 minutes c) Flush the eye to ... symptoms such as head ache, nose or throat irritation, dizziness or drowsiness persists, seek immediate medical attention.

Description : Which of the following ECG waveforms characterizes conduction of an electrical impulse through the left ventricle? a) QRS complex The QRS complex represents ventricular depolarization b) P ... QT interval is an ECG characteristic reflecting the time from ventricular depolarization to repolarization.

Last Answer : a) QRS complex The QRS complex represents ventricular depolarization

Description : In a three-phase electrical system, three ground detecting lamps are provided. One lamp goes dark and the others increase in brightness. When the test button is pushed, all lamps have equal illumination. You ... C. there are grounds on the lines with the bright lamps D. this is a normal condition

Last Answer : Answer: A

Description : What are the different types of faults in a transformer?

Last Answer : The internal faults include phase faults, ground faults, inter-turn faults, tap-changer failure, and leakage oil from tank. The external faults include system phase faults, system ground faults, over loads and over fluxing.