ASA electical sys

109 (8911) - If any one generator in a 24-volt dc system shows low voltage, the most likely cause is

A- an out-of-adjustment voltage regulator.

74 (8876) - A circuit breaker is installed in an aircraft electrical system primarily to protect the

A- circuit and should be located as close to the source as possible.

87 (8889) - A certain switch is described as a single-pole, double-throw switch (SPDT). The throw of a switch indicates the number of

A- circuits each pole can complete through the switch.

38 (8840) - For general electrical use in aircraft, the acceptable method of attaching a terminal to a wire is by

A- crimping.

61 (8863) - When using the voltage drop method of checking circuit resistance, the

A- input voltage must be maintained at a constant value.

10 (8812) - The method most often used in overcoming the effect of armature reaction is through the use of

A- interpoles.

126 (8928) - CSD driven generators are usually cooled by

A- oil spray.

43 (8845) - When approved, splices may be used to repair manufactured harnesses or installed wiring. The maximum number of splices permitted between any two connectors is

A- one.

103 (8905) - The overvoltage control automatically protects the generator system when excessive voltage is present by

A- opening the shunt field circuit.

64 (8866) - To help minimize radio interference a capacitor will largely eliminate and provide a steady direct current if the capacitor is connected to the generator in

A- parallel.

23 (8825) - To test generator or motor armature windings for opens,

A- place armature in a growler and connect a 110V test light on adjacent segments; light should light.

86 (8888) - In aircraft electrical systems, automatic reset circuit breakers

A- should not be used as circuit protective devices.

11 (8813) - The only practical method of maintaining a constant voltage output from an aircraft generator under varying conditions of speed and load is to vary the

A- strength of the magnetic field.

113 (8915) - Major adjustments on equipment such as regulators, contactors, and inverters are best accomplished outside the airplane on test benches with necessary instruments and equipment. Adjustment procedure should be as outlined by

A- the equipment manufacturer.

18 (8820) - The type of electric wire terminals used for most aircraft applications, in addition to providing good current carrying capabilities, are designed primarily

A- to prevent circuit failure due to terminal disconnection.

120 (8922) - How is a shunt-wound dc generator connected?

B- Both fields are shunted across the armature.

30 (8832) - What does a rectifier do?

B- Changes alternating current into direct current.

50 (8852) - What is normally used to bond noncontinuous stainless steel aircraft components?

B- Copper jumpers.

34 (8836) - Which of the following is most likely to cause thermal runaway in a nickel-cadmium battery?

B- Excessive current draw from the battery.

7 (8809) - What is required when operating two aircraft ac generators in parallel?

B- Frequency and voltage must both be equal.

75 (8877) - How should a voltmeter be connected?

B- In parallel with the load.

55 (8857) - Oil canning of the sides of aluminum or steel electrical junction boxes is considered to be

B- a shorting hazard.

29 (8831) - During ground operation, aircraft generator cooling is usually accomplished by

B- an integral fan.

6 (8808) - What is a cause of generator brush arcing?

C- Low spring tension.

92 (8894) - Why are the iron cores of most induction coils laminated?

C- To reduce the effects of eddy currents.

116 (8918) - The purpose of a rectifier in an electrical system is to change

C- alternating current to direct current.

99 (8901) - The inductor-type inverter output voltage is controlled by the

C- dc stator field current.

32 (8834) - When a diode is checked for an open circuit or a short circuit, it should be

C- disconnected from the circuit.

67 (8869) - Electric circuits are protected from overheating by means of

C- fuses.

19 (8821) - Aluminum wire must be stripped very carefully because

C- individual strands will break easily after being nicked.

17 (8819) - A series-wound dc electric motor will normally require

C- more current at low RPM than at high RPM.

131 (8933) - A CSD unit that is disconnected in flight, due to a malfunction such as overtemperature, may be reconnected

C- only on the ground by maintenance personnel.

14 (8816) - If the reverse current cutout relay contact points fail to open after the generator output has dropped below battery potential, current will flow through the generator armature

C- opposite the normal direction and through the shunt field in the normal direction.

102 (8904) - A voltage regulator controls generator voltage by changing the

C- resistance of the generator field circuit.

100 (8902) - When using an ohmmeter to check the continuity of a generator field coil, the coil should

C- show very low resistance if it is a series field coil.

63 (8865) - Aircraft electrical junction boxes located in a fire zone are usually constructed of

C- stainless steel.

106 (8908) - The most common method of regulating the voltage output of a compound dc generator is to vary the

A- current flowing through the shunt field coils.

65 (8867) - The primary considerations when selecting electric cable size are

A- current-carrying capacity and allowable voltage drop.

5 (8807) - If a generator is equipped with a vibrator-type voltage regulator, the actual time the voltage regulator points remain open

A- depends on the load carried by the generator.

94 (8896) - The voltage in an ac transformer secondary that contains twice as many loops as the primary will be

A- greater and the amperage less than in the primary.

53 (8855) - Circuits that must be operated only in an emergency or whose inadvertent activation could endanger a system frequently employ

A- guarded switches.

72 (8874) - Bonding connections should be tested for

A- resistance value.

132 (8912.2) - Static inverters are electronic devices that change DC to AC with the

A- use of an oscillator.

77 (8879) - If it is necessary to use an electrical connector where it may be exposed to moisture, the mechanic should

B- use a special moisture-proof type.

85 (8887) - Where electric cables must pass through holes in bulkheads, formers, ribs, firewalls, etc., the wires should be protected from chafing by

B- using a suitable grommet.

47 (8849) - The voltage output of an alternator may be regulated by controlling the

B- voltage output of the dc exciter.

90 (8892) - The circuit breaker in the instrument lighting system protects the

B- wiring from too much current.

70 (8872) - In installations where the ammeter is in the generator or alternator lead, and the regulator system does not limit the maximum current that the generator or alternator can deliver, the ammeter can be redlined at what percent of the generator or alternator rating?

C- 100

107 (8909) - (Refer to Figure 18.) Which of the batteries are connected together incorrectly?

C- 3

81 (8883) - What is the voltage drop for a No. 18 copper wire 50 feet long to carry 12.5 amperes, continuous operation?Use the formula (VD =RLA)VD = Voltage drop,R = Resistance per ft = .00644,L = Length of wireA = Amperes

C- 4V.

15 (8817) - How does the magnetic brake used to stop rotation of an electric motor armature operate?

C- A friction brake is applied by a spring and released by a magnet.

89 (8891) - What is an important factor in selecting aircraft fuses?

C- Capacity matches the needs of the circuit.

68 (8870) - How does the routing of coaxial cables differ from the routing of electrical wiring?

C- Coaxial cables are routed as directly as possible.

25 (8827) - To what depth is the mica insulation between the commutator bars of a dc generator undercut?

C- Equal to the width of the mica.

84 (8886) - What is the advantage of a current limiter?

C- It will take overload for a short period.

59 (8861) - Which of the following should be accomplished in the installation of aircraft wiring?

C- Locate the bundle above flammable fluid lines and securely clamp to structure.

79 (8881) - If a wire is installed so that it comes in contact with some moving parts, what protection should be given the wire?

C- Pass through conduit.

118 (8920) - In an ac circuit with no phase lead or lag, which is true?

C- Real power equals apparent power.

83 (8885) - What is the advantage of a circuit breaker when compared to a fuse?

C- Resettable and reusable.

3 (8805) - Electric wire terminals for most aircraft applications must be what type?

C- Ring.

108 (8910) - (Refer to Figure 19.) Upon completion of the landing gear extension cycle, the green light illuminated and the red light remained lit. What is the probable cause?

C- Short in the up limit switch.

35 (8837) - How can it be determined if a transformer winding has some of its turns shorted together?

C- The transformer will get hot in normal operation.

82 (8884) - What is the purpose of the selection of derated switches for known continuous load current applications?

C- To obtain reasonable switch efficiency and service life.

128 (8930) - Integrated drive generators (IDG) employ a type of high output ac generator that utilizes

C- a brushless system to produce current.

2 (8804) - One purpose of a growler test is to determine the presence of

C- a shorted armature.

127 (8929) - A CSD unit drives a generator through the use of

C- a variable hydraulic pump and hydraulic motor.

51 (8853) - Aircraft fuse capacity is rated in

C- amperes.

60 (8862) - If the (+) terminal of a voltmeter is connected to the (-) terminal of the source voltage and the (-) terminal of the meter is connected to the (+) terminal of the source voltage, the voltmeter will read

C- backwards.

37 (8839) - (1) There are three basic types of dc motors; series, shunt, and compound.(2) In the series motor, the field windings, consisting of relatively few turns of heavy wire, are connected in series with the armature winding.Regarding the above statements,

C- both No. 1 and No. 2 are true.

97 (8899) - The major advantages of alternating current (AC) over direct current (DC) is the fact that its current and voltage can easily be increased or decreased

C- by means of a transformer.

80 (8882) - In the American Wire Gauge (AWG) system of numbers used to designate electrical wire sizes, the number assigned to a size is related to its

C- cross-sectional area.

62 (8864) - The nominal rating of electrical switches refers to continuous

C- current rating with the contacts closed.

8 (8810) - The starting current of a series-wound dc motor, in passing through both the field and armature windings, produces a

C- high starting torque.

104 (8906) - When dc generators are operated in parallel to supply power for a single load, their controls include an equalizer circuit to assure that all generators share the load equally. The equalizer circuit operates by

C- increasing the output of the low generator and decreasing the output of the high generator until they are equal.

33 (8835) - When handling a high voltage capacitor in an electrical circuit, be sure it

C- is fully discharged before removing it from the circuit.

1 (8803) - Some electric motors have two sets of field windings wound in opposite directions so that the

C- motor can be operated in either direction.

54 (8856) - If one switch is used to control all navigation lights, the lights are most likely connected

C- parallel to each other and in series with the switch.

49 (8851) - Grounding is electrically connecting a conductive object to the primary structure. One purpose of grounding is to

C- prevent development of radio frequency potentials.

21 (8823) - An ammeter in a battery charging system is for the purpose of indicating the

C- rate of current used to charge the battery.

93 (8895) - Certain transport aircraft use ac electrical power for all normal operation and battery furnished dc electrical power for standby emergency use. In aircraft of this type that operate no dc generators, the batteries are kept charged by

C- rectifiers which use the aircraft's ac generators as a source of power.

121 (8923) - The poles of a generator are laminated to

C- reduce eddy current losses.

66 (8868) - The navigation lights of some aircraft consist of a single circuit controlled by a single switch which has an ON position and an OFF position, with no additional positions possible. This switch is referred to as a

C- single-pole, single-throw (SPST), two-position switch.

112 (8914) - During inspection of an anticollision light installation for condition and proper operation, it should be determined that

C- the anticollision light can be operated independently of the position lights.

125 (8927) - In troubleshooting an electrical circuit, if an ohmmeter is properly connected across a circuit component and some value of resistance is read,

C- the component has continuity and is not open.

26 (8828) - A voltage regulator controls generator output by

C- varying current flow to generator field coil.

115 (8917) - An aircraft electrical circuit control relay is

A- an electronically operated switch.

56 (8858) - Electric wiring installed in aircraft without special enclosing means (open wiring) offers the advantages of ease of installation, simple maintenance, and reduced weight. When bundling open wiring, the bundles should

A- be limited as to the number of cables to minimize damage from a single electrical fault.

45 (8847) - The most common method of attaching a pin or socket to an individual wire in an MS electrical connector is by

A- crimping.

36 (8838) - Which of the following are the major parts of a dc motor?1. Armature assembly.2. Field assembly.3. Brush assembly.4. Commutator.5. Pole piece.6. Rheostat.7. End frame.

A- 1, 2, 3, 7.

40 (8842) - When selecting hardware for attaching bonding connections to an aircraft structure, which of the following should be considered?1. Mechanical strength.2. Allowable power loss.3. Ease of installation.4. Permissible voltage drop.5. Amount of current to be carried.6. Type of load (continuous or intermittent).

A- 1, 3, 5.

39 (8841) - Which of the following factors must be taken into consideration when determining the wire size to use for an aircraft installation?1. Mechanical strength.2. Allowable power loss.3. Ease of installation.4. Resistance of current return path through the aircraft structure.5. Permissible voltage drop.6. Current carrying capability of the conductor.7. Type of load (continuous or intermittent).

A- 2, 5, 6, 7.

96 (8898) - What is a method used for restoring generator field residual magnetism?

A- Flash the fields.

4 (8806) - What is the principal advantage of the series-wound dc motor?

A- High starting torque.

98 (8900) - Which of the following must be accomplished when installing an anticollision light?

A- Install a switch independent of the position light switch.

28 (8830) - What is the most accurate type of frequency-measuring instrument?

A- Integrated circuit chip having a clock circuit.

31 (8833) - What type of instrument is used for measuring very high values of resistance?

A- Megohmmeter.

117 (8919) - What is the ratio of turns between the primary coil winding and the secondary coil winding of a transformer designed to triple its input voltage?

A- Primary will have one-third as many turns as its secondary.

22 (8824) - Which of the following is not one of the purposes of interpoles in a generator?

A- Reduce field strength.

73 (8875) - What kind of switch should you install in a single wire circuit that required the switch to be manually held in the ON position?

A- Single-pole, single-throw (SPST), two-position normally open (NO).

41 (8843) - How should the splices be arranged if several are to be located in an electrical wire bundle?

A- Staggered along the length of the bundle.

42 (8844) - What is the minimum bend radius for an electrical wire bundle?

A- Ten times the outside diameter of the bundle.

16 (8818) - In a generator, what eliminates any possible sparking to the brush guides caused by the movement of the brushes within the holder?

A- The brush pigtail.

111 (8913) - Aircraft which operate only ac generators (alternators) as a primary source of electrical power normally provide current suitable for battery charging through the use of

A- a stepdown transformer and a rectifier.

130 (8932) - When necessary during operation, CSD disconnect is usually accomplished by

A- a switch in the cockpit.

119 (8921) - How are generators rated?

B- Amperes at rated voltage.

9 (8811) - Which motor would be most likely to have an armature brake?

B- Landing light retraction motor.

24 (8826) - What is the color and orientation of the position lights for navigation on civil airplanes?

B- Left side - red, right side - green, rear aft - white.

58 (8860) - What protection to wires and cables does conduit provide when used in aircraft installations?

B- Mechanical.

69 (8871) - Which of the following copper electrical cable sizes should be selected to replace a No. 6 aluminum electrical cable?

B- No. 6.

122 (8924) - What is the frequency of an alternator dependent upon?

B- RPM.

110 (8912.1) - How can the direction of rotation of a dc electric motor be changed?

B- Reverse the electrical connections to either the field or armature windings.

27 (8829) - Which type of dc generator is not used as an airplane generator?

B- Series wound.

101 (8903) - The strength of the core of an electromagnet depends upon the material from which it is constructed and which of the following?

B- The number of turns of wire in the coil and the amount of current (amperes) passing through the coil.

13 (8815) - How many cycles of ac voltage are produced in a six-pole alternator of the revolving-field type for each revolution of the rotor?

B- Three.

105 (8907) - What is the maximum amount of time a circuit can be in operation and still be an intermittent duty circuit?

B- Two minutes.

71 (8873) - Which statement relating to electric wiring is true?

B- When attaching a terminal to the end of an electric cable, it should be determined that the strength of the cable-to-terminal joint is at least equal to the tensile strength of the cable itself.

114 (8916) - A battery-generator system provides direct current. On installations requiring alternating current from the battery-generator system, it is necessary to have

B- an inverter.

20 (8822) - The commutator of a generator

B- changes alternating current produced in the armature into direct current as it is taken from the armature.

78 (8880) - The three kinds of circuit-protection devices used most commonly in aircraft circuits are

B- circuit breakers, fuses, and current limiters.

88 (8890) - When considering an alteration, the criteria upon which the selection of electric cable size should be based are

B- current-carrying capacity and allowable voltage drop.

48 (8850) - If several long lengths of electrical cable are to be installed in rigid conduit, the possibility of damage to the cable as it is pulled through the conduit will be reduced by

B- dusting the cable with powdered soapstone.

12 (8814) - The pole pieces or shoes used in a dc generator are a part of the

B- field assembly.

124 (8926) - Residual voltage is a result of magnetism in the

B- field shoes.

123 (8925) - The generator rating is usually found stamped on the

B- generator.

91 (8893) - One advantage of using ac electrical power in aircraft is

B- greater ease in stepping the voltage up or down.

76 (8878) - A circuit protection device called a current limiter is essentially a slow-blow fuse and is designed to be used in

B- heavy power circuits.

44 (8846) - AN/MS electrical connectors are specifically designed to meet

B- military specifications.

129 (8931) - If the Integrated Drive Generator (IDG) scavenge oil filter is contaminated with metal, you should

B- remove and replace the IDG.

95 (8897) - If the positive field lead between a generator and a generator control panel breaks and is shorted while the engine is running, a voltmeter connected to generator output would indicate

B- residual voltage.

52 (8854) - When adding a rheostat to a light circuit to control the light intensity, it should be connected in

B- series with the light.

46 (8848) - The pin section of an AN/MS connector is normally installed on

B- the ground side of a circuit.

57 (8859) - During inspection of the terminal strips of an aircraft electrical system, it should be determined that

B- the terminal studs are anchored against rotation.