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
Description : The leads from a megohmmeter are attached to the leads of an AC motor field coil. A reading of infinity is obtained indicating a/an ____________. A. open field coil B. shorted field coil C. grounded field coil D. shunted field coil
Last Answer : Answer: A
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 : When testing a capacitor with an analog type ohmmeter, a good capacitor will be indicated when _____________. A. there is no meter deflection B. the meter deflects to a low resistance value and ... deflects to a low resistance value and increases rapidly to a higher value, but stays fairly low
Last Answer : Answer: C
Description : You are performing an out-of-circuit test of the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' position and with leads properly installed, which of the listed results would indicate a good ... lead on 'A' and red lead on 'C'; and a high reading with the leads reversed.
Description : You are performing an out-of-circuit test on the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' setting and with leads properly inserted, which of the listed results would indicate a good ... lead on 'A' and red lead on 'C'; and a high reading with the leads reversed.
Last Answer : Answer: D
Description : With both ends of a three conductor cable disconnected and arranged without the conductors touching each other, an ohmmeter reading of 'zero' ohms between the ends of one conductor would indicate _____________. A. continuity B. a partial ground C. the resistance is infinite D. a short circuit
Description : Which of the listed statements is correct when using an analog multimeter as an ohmmeter? A. The pointer should be adjusted to zero each time a new resistance range is selected. B. The ... C. Ohmmeters are not sufficiently sized to measure conductor insulation resistance. D. All of the above.
Description : 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 ... of the component isolated. D. The meter case must be grounded prior to attaching the leads.
Description : A grounded switch or cable will be indicated by a megohmmeter reading of _____________. A. infinity B. 'zero' C. being unsteady in the high range D. being unsteady in the low range
Description : The final step in testing a circuit for a ground involves the use of a megohmmeter. A grounded switch or cable will be indicated by a megohmmeter reading of ____________. A. 'zero' B. infinity C. steady in the high range D. unsteady in the low range
Description : The ground indicating light on the main electrical switchboard is indicating a ground. The best procedure for locating the grounded circuit is to _____________. A. trace the circuit paths while looking for ... a time, until the lights no longer indicate a ground D. check all circuits for continuity
Description : A capacitor can be tested using a megohmmeter or an ohmmeter. If the meter is connected to a shorted capacitor, the meter pointer should _____________. A. immediately swing to the maximum resistance ... deflect to and remain at zero D. immediately swing to a high reading and then gradually decrease
Description : When a megohmmeter is being used on a alternating current machine, the meter pointer will dip toward 'zero' and then gradually rise to the true resistance value if the motor insulation is _____________. A. grounded B. good C. shorted D. dirty
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
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
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
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
Description : You have installed a Zener diode in parallel with a load. While measuring the voltage across the Zener diode it is found that it does not change as the current through the load increases. This means that the ... is working as it should B. is shorted C. is open D. does not regulate as it should
Description : When you are using an ohmmeter to test a transistor for leakage, what is indicated by a low, but not shorted, reverse resistance reading?
Last Answer : A leaking transistor
Description : When using the test set-up shown in the illustration, the lighted lamp indicates the winding is ____________. EL-0027 A. grounded B. good C. open D. shorted
Description : When troubleshooting AC motors, a portable growler can be used for locating ____________. A. open field coils B. grounded field coils C. grounded stator coils D. shorted stator coils
Description : When testing an SCR with an ohmmeter, the SCR will conduct if what two elements are shorted together?
Last Answer : Gate and anode.
Description : You are performing an out-of-circuit test of the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' position and with leads properly installed, which of the listed results would you expect the ... lead on 'B' and black lead on 'A'; and a low reading with the leads reversed.
Description : Forward current through a semi-conductor diode circuit is due to ________ (a) Minority carriers (b) majority carriers (c) holes (d) electrons
Last Answer : (b) majority carriers
Description : A testing device called a 'growler' is being used to locate a shorted coil in the stator of an AC electrical machine. When the 'feeler' is moved over a slot containing the shorted coil _____________. ... . the meter needle will be deflected to zero D. the meter needle will be deflected to full-scale
Description : In which of the situations listed will a megohmmeter give the most accurate readings? A. While the machine is in operation. B. While the machine is discharging static electricity. C. Immediately prior to ... machine. D. When the machine has been shut down and grounded for a period of 15 minutes.
Description : Conductor resistance may be INDIRECTLY measured by using a/an _____________. A. voltmeter only B. ammeter only C. voltmeter and an ammeter D. ohmmeter only
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.
Description : A generator has been exposed to water and is being checked for its safe operation. Therefore, it is necessary to _______________. A. check for shorted coils with a growler B. take moisture readings with a ... a megger D. ground the commutator, or slip rings and run it at half load for 12 hours
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
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.
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
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
Description : A megohmmeter can be used to test for _____________. A. an open field coil B. a shorted field pole C. undercut mica D. reversed polarity
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 : Junction breakdown occurs: a) With forward bias b) With reverse bias c) Under high temperature condition d) Because of excess heating of the diode
Last Answer : Ans: B
Description : Which of the following conditions indicates a short circuited capacitor when checking its condition with an ohmmeter? A. The capacitor shows charging, but the final resistance reading is appreciably less ... moves quickly to the low resistance side of the scale, then slowly recedes toward infinity.
Description : In the system shown in the illustration, the station at section I is unable to signal any other station nor is any other station able to signal the station in section I. The station can, however, ring ... only a single station to respond to itself. D. The switch at component 'C' is stuck open.
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 : One diode of a full-wave rectifier has burned out in a shorted condition. Therefore, the output will be ____________. A. zero B. a rectified half-wave C. a rectified full-wave D. equal to the AC input
Description : A low voltage source is being used for testing armature coils. A coil short circuit will be indicated by a _______. A. high voltage reading, while the other coil readings will have an ... the other coil readings are steady D. steady voltmeter reading, while the other coil readings are fluctuating
Description : Violent gassing from a lead-acid battery while it is being charged, indicates that the _____________. A. plate separators are grounded B. battery compartment ventilation is inadequate C. electrolyte specific gravity is too low D. charging rate is too high
Description : While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started ... field windings are grounded C. slip rings are dirty D. power transmission cables are grounded
Description : You have just checked a fuse with an ohmmeter and find that the fuse is shorted. What should you
Last Answer : Put it back in the circuit. A good fuse will have zero ohms of resistance.
Description : The vertical dotted line connecting the small circular symbols at coordinates '05L', '09L', '13L', '21L', '25L', etc., shown in the illustration, indicate that all _______________. EL-0100 A. contacts are ... board 'TB2' C. wires are grounded at both ends of the line D. wires have a common shield
Description : The potentiometers shown in the illustration are supplied with both (+) and (-) voltages as well as a reference to ground ________________. EL-0095 A. so there is always a spare power ... , the other for relay operation and the potentiometers are in positions where they can be accidentally touched
Description : An ohmmeter used to test for front-to-back resistance of a PN junction diode should produce roughly what ratio? A. 100:01:00 B. 500:01:00 C. 1000:01:00 D. 5000:01:00
Description : Photo diode operates in the _______ condition (a) Forward bias (b) null (c) both a & d (d) reverse bias
Last Answer : (d) reverse bias
Description : The following air gap readings were obtained from a horizontally mounted, bilge pump, induction motor, equipped with sleeve bearings: FWD END-AFT END, Top .045 - .049, Right Side .045 - .047, Left ... the aft bearing. C. The forward bearing should be lowered. D. The aft bearing should be lowered.