While troubleshooting a circuit in an engine room central control console, a resistor is suspected of being faulty. Which of the following precautions must be observed if an ohmmeter is to be used to check its value? A. Correct polarity must be observed because reverse bias will damage the component. B. Meter leads must not be twisted so as to cancel out the individual magnetic fields. C. Resistor's circuit must be de-energized and at least one end of the component isolated. D. The meter case must be grounded prior to attaching the leads.

While troubleshooting a circuit in an engine room central control console, a resistor is suspected of being faulty. Which of the following precautions must be observed if an ohmmeter is to be used to check its value? A. Correct polarity must be observed because reverse bias will damage the component. B. Meter leads must not be twisted so as to cancel out the individual magnetic fields. C. Resistor's circuit must be de-energized and at least one end of the component isolated. D. The meter case must be grounded prior to attaching the leads.
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Answer: C
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Related questions

When troubleshooting a console circuit card which is suspected of being faulty, the first step would be to _____. A. pull the card and measure the value of all resistors B. check for the correct value and polarity of all power connections to the card C. de-energize and pull the card to visually inspect for burned components D. check for continuity of circuit board traces and then the gain of each transistor

Description : When troubleshooting a console circuit card which is suspected of being faulty, the first step would be to _____. A. pull the card and measure the value of all resistors B. check for the ... for burned components D. check for continuity of circuit board traces and then the gain of each transistor

Last Answer : Answer: C

When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors are tight B. test each resistor and capacitor on the card with an ohmmeter C. check the continuity of all printed circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit

Description : When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors ... circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit

Last Answer : Answer: A

When troubleshooting a console circuit card suspected of being faulty, the last step would be to _______________. A. check the fuses and voltage levels of all power supplies in the console B. clean dust and debris from the card and burnish the sliding connections C. make sure all connections are tight including wire wrappings and push-on types D. substitute a new or repaired spare card and check the operation of the circuit

Description : When troubleshooting a console circuit card suspected of being faulty, the last step would be to _______________. A. check the fuses and voltage levels of all power supplies in the console B. clean dust ... -on types D. substitute a new or repaired spare card and check the operation of the circuit

Last Answer : Answer: D

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. Testing an energized circuit presents a hazard to the testing personnel. B. A faulty fuse could go undetected with the motor energized. C. Reversed polarity of the circuit would be indicated by the voltage tester with the circuit energized. D. All of the above.

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.

Last Answer : Answer: B

When troubleshooting electronic equipment, the FIRST step to be taken before testing the circuit voltage is to _________. A. set the meter to the lowest range B. check the voltage supply from the power source C. remove the suspected component D. check the current flow through the circuit

Description : When troubleshooting electronic equipment, the FIRST step to be taken before testing the circuit voltage is to _________. A. set the meter to the lowest range B. check the voltage supply from the power source C. remove the suspected component D. check the current flow through the circuit

Last Answer : Answer: B

When a console indicating lamp burns out, attempts to renew it should not be made while maneuvering because _______________. A. the new lamp may be of a higher wattage and cause heat damage to the lens B. removing a faulty lamp usually causes an alarm to sound on the bridge C. attention should be paid only to engine orders D. a socket/wiring fault may cause a ground or short circuit to shut down a vital function

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Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer to 'zero'. This is most likely an indication of ______ A. an improper resistance range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement

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Last Answer : Answer: B

What is the direction of current through the load resistor in the circuit shown in the illustration? EL-0085 A. Always from point 'Z' to the grounded end. B. Always from the grounded end to point 'Z'. C. It depends on the instantaneous polarity at point 'W'. D. It cannot be determined without a directional ammeter.

Description : What is the direction of current through the load resistor in the circuit shown in the illustration? EL-0085 A. Always from point 'Z' to the grounded end. B. Always from the grounded end to ... on the instantaneous polarity at point 'W'. D. It cannot be determined without a directional ammeter.

Last Answer : Answer: B

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 control fuse C. a reading of 'zero' on a megger from one of the coil's leads to ground D. a higher-than-normal voltage reading across the winding

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Last Answer : Answer: B

To avoid damaging the components of a printed circuit board when testing it with a DC volt-ohmmeter, you should _______. A. ground the board B. avoid reversing the polarity of the leads C. isolate sensitive components with heat sinks D. all of the above

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Last Answer : Answer: B

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

When troubleshooting electronic equipment, you should use a high impedance multimeter ________________. A. to prevent excess current flow through the meter that would damage it B. for AC measurements only and a low resistance meter for DC measurements C. whenever a low impedance meter is not available, regardless of the components being tested D. so as not to load down the circuit and obtain erroneous voltage readings

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Last Answer : Answer: D

While testing a semi-conductor diode with an ohmmeter, both the forward and reverse readings are almost in the infinity range. This would indicate that the unit is _____________. A. good B. open C. grounded D. shorted

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Last Answer : Answer: B

When troubleshooting a motor controller, all indications are that a relay coil should be energized. If there were no magnetic pull, with rated voltage measured across the coil, the most probable cause would be that the _________________. A. coil is open B. control fuse is open C. auxiliary contact in series with the coil is defective D. relay armature is stuck

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Last Answer : Answer: A

A faulty 'function generator' shown in the illustration may prevent _____________. EL-0095 A. proper pitch control from both the 'bridge' and 'engine room thrust levers' B. the 'split potentiometer's' ability to control pitch C. the pitch meter from indicating accurately D. relays #2 and/or #3 from energizing

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Last Answer : Answer: A

The first requirement for logical troubleshooting of any system is the ability to ______________. A. collect all available data on a casualty B. recognize normal operation C. identify the probable cause of a symptom D. isolate the faulty component

Description : The first requirement for logical troubleshooting of any system is the ability to ______________. A. collect all available data on a casualty B. recognize normal operation C. identify the probable cause of a symptom D. isolate the faulty component

Last Answer : Answer: B

When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment away. B. Measure capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

Description : When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment ... capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

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When measuring AC current flow, you must always connect the meter _____________. A. in series with the power source and load B. in parallel with the power source and load C. insuring correct polarity D. using the lowest range possible to prevent instrument damage

Description : When measuring AC current flow, you must always connect the meter _____________. A. in series with the power source and load B. in parallel with the power source and load C. insuring correct polarity D. using the lowest range possible to prevent instrument damage

Last Answer : Answer: A

An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges

Description : An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges

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Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent short circuiting. B. only be connected to multimeter on the ammeter setting C. be short circuited D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

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Last Answer : Answer: C

When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Description : When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Last Answer : Answer: C

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 : 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

Last Answer : Answer: B

A voltmeter located on a control panel has been operating correctly for six months, suddenly burns out. After removing it, it is found that neither side of the meter has been grounded. When installing the new meter it should be __________. A. grounded to the negative side B. connected to a large resistor between the positive side and the ground C. installed exactly as the old installation D. grounded to the positive side

Description : A voltmeter located on a control panel has been operating correctly for six months, suddenly burns out. After removing it, it is found that neither side of the meter has been grounded. When ... side and the ground C. installed exactly as the old installation D. grounded to the positive side

Last Answer : Answer: C

In the illustration, the tan and white wires are connected to the solenoid valve. The solinoid valve is_________. EL-0043 A. in the liquid line before the TXV B. energized and open whenever the unit is plugged in C. not grounded so the unit must be modified before using aboard ship D. the water inlet for the ice maker

Description : In the illustration, the tan and white wires are connected to the solenoid valve. The solinoid valve is_________. EL-0043 A. in the liquid line before the TXV B. energized and open whenever the unit ... so the unit must be modified before using aboard ship D. the water inlet for the ice maker

Last Answer : Answer: D

In the illustration, the tan and white wires are connected to the solenoid valve. The solenoid valve is_________. EL-0042 A. in the liquid line before the TXV B. energized and open whenever the unit is plugged in C. not grounded so the unit must be modified before using aboard ship D. the water inlet for the ice maker

Description : In the illustration, the tan and white wires are connected to the solenoid valve. The solenoid valve is_________. EL-0042 A. in the liquid line before the TXV B. energized and open whenever the unit ... so the unit must be modified before using aboard ship D. the water inlet for the ice maker

Last Answer : Answer: D

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

Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include ______________. A. systematic rotation of circuit cards with those from spares to allow component cooling B. periodic changing or cleaning of console ventilation and control room air conditioning filters C. weekly tightening of console foundation bolts and changing of the air in the control room D. all of the above

Description : Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include ______________. A. systematic rotation of circuit cards with those ... bolts and changing of the air in the control room D. all of the above

Last Answer : Answer: B

Prior to using an analog type ohmmeter, the leads are purposely shorted together. Which of the following actions should be taken if, when adjusting to 'zero' ohms, the indicating needle can not be returned to 'zero' on the scale? A. The lead clips should be replaced. B. The batteries should be replaced. C. The test reading should be added to each final reading. D. The test reading should be subtracted from each final reading.

Description : Prior to using an analog type ohmmeter, the leads are purposely shorted together. Which of the following actions should be taken if, when adjusting to 'zero' ohms, the indicating needle can not be ... be added to each final reading. D. The test reading should be subtracted from each final reading.

Last Answer : Answer: B

According to Coast Guard Regulations (46 CFR), which of the following systems must be arranged so as to be energized by the final emergency power source? A. at least one light in the steering gear room B. each power operated watertight door system C. each charging panel for temporary emergency batteries D. all of the above

Description : According to Coast Guard Regulations (46 CFR), which of the following systems must be arranged so as to be energized by the final emergency power source? A. at least one light in the ... operated watertight door system C. each charging panel for temporary emergency batteries D. all of the above

Last Answer : Answer: D

When troubleshooting an electronic circuit, a cold solder joint can be located with the aid of an ohmmeter. Once the problem has been located, you should _________________. A. reheat the circuit in an oven to an even temperature and recheck with an ohmmeter B. reheat the connection with a match and recheck with an ohmmeter C. reheat connection with a soldering tool and recheck with an ohmmeter D. do nothing as this is the normal condition

Description : When troubleshooting an electronic circuit, a cold solder joint can be located with the aid of an ohmmeter. Once the problem has been located, you should _________________. A. reheat the circuit in an ... a soldering tool and recheck with an ohmmeter D. do nothing as this is the normal condition

Last Answer : Answer: C

One of the following is a possible cause for a slow drift of frequency in a self-exited transmitter oscillator circuits resulting to a poor frequency stability. A. Loose shielding B. Heating of capacitor in the oscillator C. Poor soldered connections D. Faulty capacitor, resistor, tubes or resistors

Description : One of the following is a possible cause for a slow drift of frequency in a self-exited transmitter oscillator circuits resulting to a poor frequency stability. A. Loose shielding B. ... capacitor in the oscillator C. Poor soldered connections D. Faulty capacitor, resistor, tubes or resistors

Last Answer : B. Heating of capacitor in the oscillator

In order to check the performance of a transistor removed from its circuit, the instrument to be used should be a/an ____________. A. voltmeter or transistor tester B. impedance meter C. ohmmeter or transistor tester D. sensitive potentiometer

Description : In order to check the performance of a transistor removed from its circuit, the instrument to be used should be a/an ____________. A. voltmeter or transistor tester B. impedance meter C. ohmmeter or transistor tester D. sensitive potentiometer

Last Answer : Answer: C

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 : 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

Last Answer : Answer: B

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 remove fuse from the circuit. C. Replace blown fuse with one of equal voltage and ampere capacity. D. Fuses of 10 ampere rating and less are virtually harmless when energized and may be handled freely.

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.

Last Answer : Answer: C

An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically equalize the power factors C. reverse the direction of current in the series field of the incoming generator D. parallel the series fields of the generators

Description : An equalizing connection between two compound-wound DC generators when paralleled, serves to _____________. A. reverse the polarity of the incoming generator as the series field weakens B. automatically ... the series field of the incoming generator D. parallel the series fields of the generators

Last Answer : Answer: D

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

Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointers to mid-scale B. change the meter's batteries C. center the meter's pointer at infinity D. short the test leads and calibrate the meter

Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointers to mid-scale B. change the meter's batteries C. center the meter's pointer at infinity D. short the test leads and calibrate the meter

Last Answer : Answer: D

Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointer to mid-scale B. short the test leads and calibrate the meter reading to 'zero' C. change the meter's batteries D. center the meter's pointer at infinity

Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointer to mid-scale B. short the test leads and calibrate the meter reading to 'zero' C. change the meter's batteries D. center the meter's pointer at infinity

Last Answer : Answer: B

As shown in the illustration, the direction of electron flow through the component is _______. EL-0079 A. from terminal 'B' to terminal 'A' B. from terminal 'A' to terminal 'B' C. determined by the polarity of the applied voltage D. opposite from that in a resistor

Description : As shown in the illustration, the direction of electron flow through the component is _______. EL-0079 A. from terminal 'B' to terminal 'A' B. from terminal 'A' to terminal 'B' C. determined by the polarity of the applied voltage D. opposite from that in a resistor

Last Answer : Answer: B

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 B. help the windings to cool to ambient temperature C. release any residual capacitive charge from the windings D. help the windings to cool to the same temperature as the ground test connection

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

Last Answer : Answer: C

When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

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Last Answer : Answer: D

When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Description : When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Last Answer : Answer: D

While paralleling two (2) AC generators using synchronizing lamps only, both lamps will go dark when the generators are ____________. A. running at the same speed B. grounded C. of the same polarity D. in phase

Description : While paralleling two (2) AC generators using synchronizing lamps only, both lamps will go dark when the generators are ____________. A. running at the same speed B. grounded C. of the same polarity D. in phase

Last Answer : Answer: D

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 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

Last Answer : Answer: B