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'
Last Answer : Answer: C
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
Last Answer : Answer: A
Description : Before touching a small capacitor connected to a de-energized circuit, or even one that is completely disconnected, you should ____________. A. gently tap the body with a screwdriver B. tag it ... insulated fuse puller D. short circuit the terminals to make sure that the capacitor is discharged
Last Answer : Answer: D
Description : When changing fuses and the spring clips are found to have lost their grip, they should be replaced or _____________. A. tightened firmly with insulated pliers B. clip clamps should be used C. wired closed with uninsulated, varnished copper wire D. carefully bent back to their original shapes
Last Answer : Answer: B
Description : When removing ball or roller bearings from the shaft of a motor, you should use a _____________. A. rawhide hammer B. brass mallet C. wheel puller D. soft iron pry bar
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.
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 : When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across ... of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester
Description : If a voltage tester is being used to check for defective fuses in the circuit, shown in the illustration, which of the readings will indicate that fuse #2 is open? EL-0062 A. C-B full voltage B. A-D full voltage C. A-D no voltage D. C-B no voltage
Description : You are using a mechanical voltage tester to check the fuses in a three-phase circuit supplying an electric motor. For which of the following reasons must the motor be stopped during the test? A. ... circuit would be indicated by the voltage tester with the circuit energized. D. All of the above.
Description : A 'dead front' switchboard is one _____________. A. without switches on it B. with insulated switches and no exposed terminals C. without circuit breakers D. without safety hand rails nor rubber mats
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 : Due to the operating characteristics of the system, time lag fuses (or dual-element fuses) are necessary for use in _____________. A. main lighting circuits B. motor starting circuit C. emergency lighting circuits D. general alarm circuits
Description : Coast Guard Regulations (46 CFR) require that each alternating current generator arranged for parallel operation shall be provided with _____________. A. more than one means of excitation B. individual circuit fuses C. a high back-pressure trip D. a reverse-power trip
Description : Fuses are usually rated in _____________. A. watts B. amps only C. volts only D. amps and volts
Description : To check the three line fuses of a three-phase system consisting of a three-phase motor, you must _____________. A. place the starter in the 'stop' position B. make sure the motor is operating at full ... leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses
Description : Fuses are rated in _____________. A. voltage B. amperage C. interrupting capacity D. all the above
Description : Fuses placed in series with a thermal trip-type circuit breaker are used for _____________. A. time-delay protection B. short-circuit protection C. short duration surge protection D. sustained overload protection
Description : Time delayed or delayed action-type fuses are designed to _____________. A. prevent grounds in branch circuits B. prevent opens in motor circuits C. permit momentary overloads without melting D. guard lighting and electronic circuits
Description : As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to _____________. A. draw a one line diagram of the circuitry B. test all fuses and measure the line voltage C. take megger readings D. insulate the apparatus from ground
Description : What is the fate of the male gametes discharged in the synergid? (a) One fuses with the egg and other fuses with central cell nuclei. (b) One fuses with the egg, other(s) degenerates in the synergid. (c) All fuse with the egg. (d) One fuses with the egg, other(s) fuse(s) with synergid nucleus.
Last Answer : (a) One fuses with the egg and other fuses with central cell nuclei.
Description : In need of safety glasses, but I wear eyeglasses what should I look for?
Last Answer : Easy, prescription safety glasses. Wore them for years before getting lasik. They are exactly like regular glasses but with safety lenses and clip on side shields. You can just remove the side shield when not at work
Description : Can I put a dirty Rubber Mat in Washing Machine for cleaning?
Last Answer : You can but its not recommended damage to the rubber mat woould probably occur,and not to mention the possuble damage to your machine.
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 : 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 : 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 : 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 : 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.'
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 fuse that blows often should be replaced only with a fuse of _____________. A. the recommended current and voltage rating B. higher current and voltage rating C. higher current and lower voltage rating D. lower current and higher voltage rating
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
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 : List the safety precautions to be observed when checking fuses.
Last Answer : Turn the power off and discharge the circuit before you remove fuses. Use a fuse puller (an insulated tool) when you remove fuses d. Not acceptable-lower voltage rating e. Direct replacement
Description : What is a stand and mat used to hold a beaker or flask over a Bunsen burner?
Last Answer : Need answer
Description : I just bought some nice leather boots. How can I keep them nice without changing the color?
Last Answer : answer:Oil is overkill I think. It softens the leather too much. I use Aqueous Wax (the brand is Nikwax). It will darken the leather a little, you would have to test it on an ... recommends applying one annual light layer of a waterproofing product, such as Nikwax or Granger's .Backpacker Magazine
Description : Where can I buy inexpensive rubber rain boots in San Francisco?
Last Answer : Try the Nordstrom Rack. Or maybe that new TJ Maxx? Though you could easily BART to a Target.
Description : Three men are walking across a green and luscious field. Only two of them are wearing rubber boots and yet the feet of the third man remain dry. Why? -Riddles
Last Answer : The ground is not wet!
Description : Why are Wellington boots made out of rubber?
Last Answer : Feel Free to Answer
Description : If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat
Description : The speed of a synchronous motor is varied by _____________. A. interchanging any two of the three live leads B. changing the voltage of the system C. changing the input frequency D. increasing the field excitation
Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity
Description : The voltage output of an AC generator is accurately controlled by _____________. A. changing the sensitivity of the prime mover to large changes in voltage B. varying the reluctance of the air gap C. varying the DC exciter voltage D. shorting out part of the armature windings
Description : Caution must be exercised during the charging of lead-acid storage batteries as _____________. A. the acid will become weaker B. hydrogen gas is being continuously liberated C. both plates are changing chemically to lead sulfate D. lead peroxide in the negative plate is poisonous
Description : The speed of a squirrel-cage motor is usually changed by _____________. A. varying the frequency to the machine B. adding resistance in series with the stator windings C. adding resistance in parallel with the stator windings D. changing the number of connected poles in the stator
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 : The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding
Description : A degree of control over the speed of a slip ring induction motor can be obtained by _____________. A. adjusting governor linkage B. changing the number of phases to the motor C. inserting resistance into the stator circuit D. inserting resistance into the rotor circuit