Description : If a fuse of correct size and type blows frequently, ________________. A. try the next higher amperage rating B. try the next lower amperage rating C. look for trouble within the circuit D. reduce the applied voltage 10%
Last Answer : Answer: C
Description : Which of the following precautions should be taken when a blown fuse, rated at 10 amperes, is replaced? A. Short out the fuse before removing it from the circuit. B. Use needle-nose pliers to ... D. Fuses of 10 ampere rating and less are virtually harmless when energized and may be handled freely.
Description : Using a fuse whose rating is higher than necessary ________. A. endangers the apparatus it is supposed to protect B. reduces the possibility of short circuits C. increases the efficiency of the equipment by allowing more current to be used D. wastes money because they are more expensive
Last Answer : Answer: A
Description : Since fuse elements are made of zinc or any alloy of tin and lead, the melting point of the fuse element must be _____________. A. higher than that of copper B. lower than that of copper C. equal to that of copper D. reached when the conductor it is protecting becomes 'white hot.'
Last Answer : Answer: B
Description : A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset
Last Answer : Answer: D
Description : When troubleshooting motor controllers, a shorted relay or contactor coil is often indicated by _______________. A. a resistance reading of 'infinity' on an ohmmeter B. charred insulation and/or a blown ... of the coil's leads to ground D. a higher-than-normal voltage reading across the winding
Description : In order to determine whether or not 'fuse 2' shown in the illustration is defective, you should connect the voltage tester leads across points _____________. EL-0062 A. AC B. AD C. BC D. BD
Description : In order to determine whether or not 'Fuse 1', shown in the illustration is defective, you should connect the voltage tester leads across points _____________. EL-0062 A. AC B. AD C. BC D. BD
Description : Reduced voltage applied to a motor during the starting period will _____________. A. result in decreased acceleration time only B. lower the starting current and increase accelerating time C. cause a greater starting torque D. increase the starting current and pump capacity
Description : AC and DC generators are similar in that they _____________. A. both generate alternating voltages B. both rectify the voltage before delivery C. are constructed at the same physical size for the same kilowatt rating D. both supply three-phase power
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 fuse will 'blow' if _____________. A. an electric motor is stopped suddenly by opening a switch B. the flow of current to the protection device is reversed C. the electrical current exceeds the rated value of the fuse D. unequal resistors are connected in parallel
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 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 : When fuse blows?
Last Answer : When a fuse blows, you should replace the fuse and check to seewhat might have caused it to blow. It's a sign that there might besomething causing too much current to flow in the circuit.
Description : Why is My Kenwood double din DVD player blows the fuse when hooked to power please help?
Last Answer : Need answer
Description : If a fuse blows frequently, one should (a) replace it with a thin wire (b) replace it with a thick copper wire (c) replace it with a paper clip (d) call an electrician
Last Answer : Ans:(d)
Last Answer : The fuse blows off by melting.
Description : When should a fuse be replaced with a higher rated unit?
Last Answer : never
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
Description : What does the voltage rating of a fuse indicate?
Last Answer : The ability of the fuse to quickly extinguish the arc after the fuse element melts and the maximum voltage that cannot jump across the gap of the fuse after the fuse opens.
Description : In the illustration if BRANCH NO. 1 is a lighting circuit for crew's berthing, Federal Regulations (46 CFR) require the maximum fuse rating for that branch to be _________. EL-0013 A. 80% of the connected load B. 15 amps C. 20 amps D. 30 amps
Description : In the illustration if BRANCH NO. 1 is a lighting circuit for crew's berthing, 46 CFR requires the maximum fuse rating for that branch to be _________. EL-0013 A. 15 amps B. 80% of the connected load C. 20 amps D. 30 amps
Description : When replacing fuses, always make sure _______________. A. to stand on a rubber mat and use rubber gloves B. to use insulated pliers or screwdriver C. the fuse clips are straight, tight, and in good contact D. to increase the fuse rating 10% to guard against 'nuisance blowing'
Description : What is the rating of generator PT fuse?
Last Answer : 24 kV, 3.15 Amps.
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
Description : Can using a petrol with a higher octane rating than recommended provide any benefits?
Last Answer : Using a petrol with a higher octane rating than recommended may provide improved performance in some high-performance or high-compression engines, but generally does not provide any significant benefits in most engines.
Description : What happens if you use a petrol with a lower octane rating than recommended for your engine?
Last Answer : Using a petrol with a lower octane rating than recommended for your engine can cause knocking or pinging during combustion, which can damage the engine over time.
Description : Line losses in a distribution circuit are kept to a minimum by __________. A. adding rubber insulation conductors to the circuit B. using higher current and lower voltage C. increasing the number of thermal relays in the circuit D. using higher voltage and lower current
Description : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.
Last Answer : (C) less than 800 rpm.
Description : Which of the following statements about copper wire sized by the AWG rating is correct? A. Number 12 AWG wire has a higher current rating than number 10 AWG wire. B. Number 10 AWG wire has a higher ... Number 12 AWG wire at 25°C has more resistance per 1000 feet than No. 10 AWG wire at 25°C.
Description : Which of the following statements concerning copper wire sized by AWG numbers is correct? A. Number 12 AWG wire has a higher current rating than 10 AWG wire. B. Number 12 AWG wire at 25°C has more ... dielectric strength than 12 AWG wire. D. Number 12 AWG wire is larger than number 10 AWG wire.
Description : In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 6 reads line voltage, while the voltmeter reading between 2 and 6 reads 0 VAC. The problem is __________. EL- ... in the 'M' coil, 'Ma' contact/start switch or overload contacts D. fuse '10a' is blown
Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving fast in the clockwise direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... at any pointer position D. the same as the bus frequency but out of phase with it
Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving in the fast direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... the same as the bus frequency and the circuit breaker may be closed at any pointer position
Description : You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow direction. This indicates that the frequency of the incoming machine is _____________. A. higher than ... same as the bus frequency, and the circuit breaker may be closed at any pointer position
Description : The freezing point of the electrolyte in a fully charged lead-acid battery will be _____________. A. higher than in a discharged battery B. lower than in a discharged battery C. the same as in a discharged battery D. higher than in a discharged battery, but the specific gravity will be less
Description : What does the current rating of a fuse indicate?
Last Answer : The amount of current the fuse will allow without opening.
Description : Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency ... D. permit higher voltage for electric motor operation and low voltage for lighting circuits
Description : Which of the following characteristics is most critical in determining the size of the cable to be used in a particular circuit? A. voltage rating B. weight per unit length C. current rating D. inductance per unit length
Description : Define the followings. Insulation level, Rated short circuit breaking current, Making current, Short time rating, Impulse withstand voltage, Power frequency withstand voltage .
Last Answer : Insulation level - it is the combination of rated voltage, the corresponding impulse withstand voltage, which together characterize the insulation of the equipment as regards its ability to withstand ... wave of power frequency (50 Hz) which the insulation of equipment should withstand.
Description : When changing fuses, you should always _____________. A. wear rubber boots B. use a fuse puller C. stand on a rubber mat D. wear safety glasses
Description : In order to safely carry out repairs to a generator circuit breaker, it must be isolated from the bus. This is accomplished by opening the _____________. A. reverse power relay B. bus disconnect link C. generator bus fuse connections D. power directional relay
Description : If an electric motor fails to start, you should FIRST check the _____________. A. phase sequence B. ampere load C. fuse or circuit breaker D. line frequency
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 : 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 : The part of a fuse that melts and opens the circuit is made of _____________. A. copper and antimony B. steel and babbitt C. aluminum or beryllium alloy D. zinc or an alloy of tin and lead
Description : A tubular fuse should always be removed from a fuse panel with _____________. A. a screwdriver B. a pair of insulated metal pliers C. any insulated object D. fuse pullers
Description : A capacitor discolored due to excessive heat should be _____________. A. calibrated using a capactance wheatstone bridge B. replaced and the reason for the overheating found C. cooled with a spray ... purpose D. resoldered with care taken to insure that the origional cold solder joint is repaired
Description : When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately, or the resultant flashing may _____________. A. blow the lamp's circuit breaker B. explode, ... fly in all directions C. short circuit the ballast transformer D. damage the starter and the ballast