If a delicate component must be soldered into a circuit, the component may be protected from the heat of the soldering process by _____________. A. operating the soldering gun not more than 60 seconds at a time B. using a thermal shunt C. pre-oxidizing the leads to be soldered D. coating the leads to be soldered with a light oil film

If a delicate component must be soldered into a circuit, the component may be protected from the heat of the soldering process by _____________. A. operating the soldering gun not more than 60 seconds at a time B. using a thermal shunt C. pre-oxidizing the leads to be soldered D. coating the leads to be soldered with a light oil film
by

1 Answer

Answer :

Answer: B
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Related questions

When soldering a printed circuit board component, you should be careful to prevent damage by _________. A. quickly heating the joints, using a high wattage iron B. using the soldering iron tip sparingly C. using only acid cord solder D. applying mechanical pressure to the joints being soldered

Description : When soldering a printed circuit board component, you should be careful to prevent damage by _________. A. quickly heating the joints, using a high wattage iron B. using the soldering iron tip sparingly C. using only acid cord solder D. applying mechanical pressure to the joints being soldered

Last Answer : Answer: B

Why must items to be soldered be cleaned just prior to the soldering process?

Description : Why must items to be soldered be cleaned just prior to the soldering process?

Last Answer : Solder will not adhere to dirty, greasy, or oxidized surfaces.

When a solid-state component of an electronic circuit is mounted to a metallic mass, the general purpose of that mass is to ____________. A. prevent vibration damage to delicate components B. prevent mechanical damage to solid-state components C. dissipate stray magnetic currents D. act as a heat sink

Description : When a solid-state component of an electronic circuit is mounted to a metallic mass, the general purpose of that mass is to ____________. A. prevent vibration damage to delicate components B. prevent ... damage to solid-state components C. dissipate stray magnetic currents D. act as a heat sink

Last Answer : Answer: D

A capacitor discolored due to excessive heat should be _____________. A. calibrated B. replaced C. cooled D. soldered

Description : A capacitor discolored due to excessive heat should be _____________. A. calibrated B. replaced C. cooled D. soldered

Last Answer : Answer: B

What happens if a soldering gun switch is pressed for periods longer than 30 seconds?

Description : What happens if a soldering gun switch is pressed for periods longer than 30 seconds?

Last Answer : It will overheat and could burn the insulation of the wire being soldered.

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 load to guard against a false reading C. place the leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses

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

Last Answer : Answer: A

The rotation of a three-phase induction motor can be reversed by _____________. A. interchanging any two of the three line leads to the stator B. disconnecting one of the three line leads to the stator C. switching the shunt field coil leads D. permanently disconnecting any two of the three line leads to the stator

Description : The rotation of a three-phase induction motor can be reversed by _____________. A. interchanging any two of the three line leads to the stator B. disconnecting one of the three line leads to the ... the shunt field coil leads D. permanently disconnecting any two of the three line leads to the stator

Last Answer : Answer: A

Flux aids in soldering by removing what from surfaces to be soldered?

Description : Flux aids in soldering by removing what from surfaces to be soldered?

Last Answer : Oxides.

When maintaining the circuit shown in the illustration, what dangers are associated with component 'C' should it become broken? EL-0081 A. Glass fragments may cut a person's skin. B. The contained mercury vapor is highly toxic. C. The inside coating of phosphor is highly poisonous. D. All of the above.

Description : When maintaining the circuit shown in the illustration, what dangers are associated with component 'C' should it become broken? EL-0081 A. Glass fragments may cut a person's skin. B. The contained mercury ... highly toxic. C. The inside coating of phosphor is highly poisonous. D. All of the above.

Last Answer : Answer: D

Current measuring instruments must always be connected in _____________. A. series with a circuit B. parallel with a circuit C. series-parallel with a circuit D. delta with the shunt

Description : Current measuring instruments must always be connected in _____________. A. series with a circuit B. parallel with a circuit C. series-parallel with a circuit D. delta with the shunt

Last Answer : Answer: A

Why is it a poor practice to use a high wattage soldering iron when soldering or desoldering components on a printed circuit board? A. The circuit board will blister and warp. B. The foil wire bonded to the board may come loosened from the board. C. The circuit board has a low melting temperature. D. The solder is kept to a dull heat dissipating finish.

Description : Why is it a poor practice to use a high wattage soldering iron when soldering or desoldering components on a printed circuit board? A. The circuit board will blister and warp. B. The foil wire bonded ... board has a low melting temperature. D. The solder is kept to a dull heat dissipating finish.

Last Answer : Answer: B

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 of the instrument around the insulated conductor C. connect the voltage test leads to the appropriate terminals D. short the test leads and calibrate the instrument to zero

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

Last Answer : Answer: B

Porcelain must not be contaminated by handling between which two stages: A. Pre-soldering and heat treatment B. Heat treatment and opaque /bake/ stages C. Opaque and bisque stages D. Bisque and glazing stages E. First opaque bake and second opaque bake

Description : Porcelain must not be contaminated by handling between which two stages: A. Pre-soldering and heat treatment B. Heat treatment and opaque /bake/ stages C. Opaque and bisque stages D. Bisque and glazing stages E. First opaque bake and second opaque bake

Last Answer : A. Pre-soldering and heat treatment

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 _____________. A. one line terminal to each coil lead in succession B. one field coil to each adjacent field coil in turn C. any suitable ground to any available line lead D. any field pole to each field coil lead

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

Last Answer : Answer: A

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 main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

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 : 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

Last Answer : Answer: A

The proper way to apply plastic electrical tape to an electric cable splice is to _____________. A. apply tape to the braided cover, but avoid touching it B. wind the tape so that each turn overlaps the turn before it C. apply the tape in one non-overlapping layer only D. heat the tape with a soldering iron for good bonding

Description : The proper way to apply plastic electrical tape to an electric cable splice is to _____________. A. apply tape to the braided cover, but avoid touching it B. wind the tape so that each turn overlaps ... tape in one non-overlapping layer only D. heat the tape with a soldering iron for good bonding

Last Answer : Answer: B

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 : 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

Last Answer : Answer: D

In accordance with Coast Guard Regulations (46 CFR), a steering gear feeder circuit from the emergency switchboard or alternate power supply must have the capacity for continuous operation of the rudder 15° side to side in not more than 60 seconds for a A. 1/4 hour B. 1/2 hour C. 1 hour D. 2 hours

Description : In accordance with Coast Guard Regulations (46 CFR), a steering gear feeder circuit from the emergency switchboard or alternate power supply must have the capacity for continuous operation of the rudder 15° side to side in not more than 60 seconds for a A. 1/4 hour B. 1/2 hour C. 1 hour D. 2 hours

Last Answer : Answer: B

Component 'A' of section 'I' shown in the illustration represents a _____________. EL-0093 A. sealed junction box B. bell C. buzzer D. shunt

Description : Component 'A' of section 'I' shown in the illustration represents a _____________. EL-0093 A. sealed junction box B. bell C. buzzer D. shunt

Last Answer : Answer: B

How should a delicate instrument be protected from a magnetic field?

Description : How should a delicate instrument be protected from a magnetic field?

Last Answer : By shielding or surrounding the instrument with a soft iron case, called a magnetic shield or screen.

A circuit is protected from overheating by a/an ___________. A. pyrometer B. thermal overload relay C. magnetic contactor D. overload transformer

Description : A circuit is protected from overheating by a/an ___________. A. pyrometer B. thermal overload relay C. magnetic contactor D. overload transformer

Last Answer : Answer: B

A device used in an electrical circuit to change alternating current to direct current, is known as a _____________. A. current transformer B. rectifier C. condenser D. shunt

Description : A device used in an electrical circuit to change alternating current to direct current, is known as a _____________. A. current transformer B. rectifier C. condenser D. shunt

Last Answer : Answer: B

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 : 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

Last Answer : Answer: A

When a resistor is used as a shunt and is connected in parallel with a meter movement coil, it will provide _____________. A. a measurement of circuit resistance B. an increased accuracy of approximately 1.5 percent C. an extended meter range D. none of the above

Description : When a resistor is used as a shunt and is connected in parallel with a meter movement coil, it will provide _____________. A. a measurement of circuit resistance B. an increased accuracy of approximately 1.5 percent C. an extended meter range D. none of the above

Last Answer : Answer: C

An adjustable resistor, whose resistance can be changed without opening the circuit in which it is connected, is called a _____________. A. bleeder resistor B. rheostat C. bridge D. variable shunt strip

Description : An adjustable resistor, whose resistance can be changed without opening the circuit in which it is connected, is called a _____________. A. bleeder resistor B. rheostat C. bridge D. variable shunt strip

Last Answer : Answer: B

The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. separate exciter in a series with the shunt field C. carbon pile regulator in series with the load D. balance coil diverting neutral current through the shunt field

Description : The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. ... in series with the load D. balance coil diverting neutral current through the shunt field

Last Answer : Answer: A

In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded for 10 minutes to remove static charges. B. The transformer connections must be made as before with regard to the indicated polarity. C. The iron core of the transformer must be flashed to pre-magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Description : In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded ... magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Last Answer : Answer: B

In a 60 Hz AC system, the current will pass through one complete cycle in _____________. A. 60 seconds B. 6 seconds C. 1 second D. .016 of a second

Description : In a 60 Hz AC system, the current will pass through one complete cycle in _____________. A. 60 seconds B. 6 seconds C. 1 second D. .016 of a second

Last Answer : Answer: D

If a DC motor runs hot, the cause may be _____________. A. high mica condition B. low ambient temperature C. clogged ventilation ducts D. an open in the shunt field

Description : If a DC motor runs hot, the cause may be _____________. A. high mica condition B. low ambient temperature C. clogged ventilation ducts D. an open in the shunt field

Last Answer : Answer: C

When using a multimeter for resistance measurements, it should be calibrated by clipping the loose ends of the leads together and _____________. A. setting the instrument pointer at 'zero' ohms B. adjusting the line voltage to calibrate the instrument C. plugging each end of one test lead into the plus and minus terminals D. using a special purpose resistance measuring instrument (a bridge)

Description : When using a multimeter for resistance measurements, it should be calibrated by clipping the loose ends of the leads together and _____________. A. setting the instrument pointer at 'zero' ohms B. ... the plus and minus terminals D. using a special purpose resistance measuring instrument (a bridge)

Last Answer : Answer: A

A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across each field coil C. using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Description : A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across ... using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Last Answer : Answer: B

When replacing a power transistor fitted with a heat sink in a circuit, a coating of silicone grease is applied between the transistor case and the heat sink. This is done to ____________. A. lubricate the transistor B. lubricate the heat sink C. aid in the removal of the heat sink D. provide maximum heat transfer

Description : When replacing a power transistor fitted with a heat sink in a circuit, a coating of silicone grease is applied between the transistor case and the heat sink. This is done to ____________. A. lubricate ... the heat sink C. aid in the removal of the heat sink D. provide maximum heat transfer

Last Answer : Answer: D

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 arc chute C. an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents

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

Last Answer : Answer: B

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 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

Which of the following statements regarding the use of a current measuring instrument is correct? A. It must be connected in series with the circuit. B. You should always start with the lowest range until a suitable reading is obtained. C. The indicating needle is deflected from left to right regardless of polarity. D. An external shunt is generally utilized where current is less than 10 amperes.

Description : Which of the following statements regarding the use of a current measuring instrument is correct? A. It must be connected in series with the circuit. B. You should always start with the lowest range ... of polarity. D. An external shunt is generally utilized where current is less than 10 amperes.

Last Answer : Answer: A

In addition to undercutting the mica, proper maintenance of a D.C. motor's commutator includes _______________. A. side-cutting the copper segments and insulating the slots B. coating the copper surface with light machine oil for the first four hours of operation C. baking the armature in an oven at a maximum of 95°C for not over 8 hours D. all of the above

Description : In addition to undercutting the mica, proper maintenance of a D.C. motor's commutator includes _______________. A. side-cutting the copper segments and insulating the slots B. coating the copper surface with light machine ... in an oven at a maximum of 95°C for not over 8 hours D. all of the above

Last Answer : Answer: A

Before using a volt-ohmmeter to measure resistance readings, you should _____________. A. replace all batteries B. test the insulation resistance of the leads C. make sure the test leads do not touch D. hold the leads together and 'zero' the meter

Description : Before using a volt-ohmmeter to measure resistance readings, you should _____________. A. replace all batteries B. test the insulation resistance of the leads C. make sure the test leads do not touch D. hold the leads together and 'zero' the meter

Last Answer : Answer: D

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 : 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

Last Answer : Answer: B

Burning of controller contacts, when opening, is prevented by _____________. A. coating the contact surfaces lightly with petroleum jelly B. magnetic blowout coils C. an overvoltage release D. an overcurrent release

Description : Burning of controller contacts, when opening, is prevented by _____________. A. coating the contact surfaces lightly with petroleum jelly B. magnetic blowout coils C. an overvoltage release D. an overcurrent release

Last Answer : Answer: B

Routine maintenance of lead acid batteries should include _____________. A. keeping the terminals clean B. coating cable connections with petroleum jelly C. maintaining a trickle charge D. all of the above

Description : Routine maintenance of lead acid batteries should include _____________. A. keeping the terminals clean B. coating cable connections with petroleum jelly C. maintaining a trickle charge D. all of the above

Last Answer : Answer: D

The arrow drawn through the component shown in the illustration means that the device's value _____________. EL-0015 A. is fixed and cannot be changed B. is variable between two limits C. has yet to be determined for the circuit application D. is not allowed to change during circuit operation

Description : The arrow drawn through the component shown in the illustration means that the device's value _____________. EL-0015 A. is fixed and cannot be changed B. is variable between two limits C. has yet to be determined for the circuit application D. is not allowed to change during circuit operation

Last Answer : Answer: B

In D.C. motor construction, the armature coils' ends are _______________. A. soldered to the commutator bar risers B. imbedded into core slots C. crimped together with brush pigtails D. spliced with the field windings

Description : In D.C. motor construction, the armature coils' ends are _______________. A. soldered to the commutator bar risers B. imbedded into core slots C. crimped together with brush pigtails D. spliced with the field windings

Last Answer : Answer: A

Thermocol (expanded polystyrene) is not used for (A) Low temperature thermal insulation as in refrigerator and air conditioners (B) Acoustic control and ceiling for building (C) High temperature thermal insulation in furnaces (D) Packing of delicate electronic gadgets

Description : Thermocol (expanded polystyrene) is not used for (A) Low temperature thermal insulation as in refrigerator and air conditioners (B) Acoustic control and ceiling for building (C) High temperature thermal insulation in furnaces (D) Packing of delicate electronic gadgets

Last Answer : (C) High temperature thermal insulation in furnaces

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 : 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

Last Answer : Answer: B