Module 3: Electric Fundamentals 1) Copper Copper losse lossess in a DC moto motorr are cause caused d by? a. High High magnet magnetic ic reluct reluctant ant circui circuitt b. High High resi resista stance nce field field windin windings gs c. Copp Copper er bear beariings ngs
2) Armatu Armature re torque torque is propo proporti rtional onal to? to? a. Fiel Field d str stren engt gth h only only b. Arma Armatu ture re curr current ent only only c. Armatu Armature re curr current ent and field field stre strengt ngth h 3) Rotational Rotational speed speed of a DC motor motor is is proporti proportional onal to to a. Armatu Armature re curr current ent and field field stre strengt ngth h b. Arma Armatu ture re curr current ent only only c. Fiel Field d str stren engt gth h only only 4) Increasing Increasing the voltage voltage applied applied to to the armature armature causes causes rotational rotational speed speed to a. Decrease b. Increase c. Stay Stay the the same same only only torq torque ue chang changes es 5) Reversing Reversing the supply to a permanent permanent magnet magnet field field motor motor causes causes a. To stop stop rot rotati ating b. Contin Continue ue to rota rotate te in in same same direct direction ion c. To rever reverse se its its rot rotat atio ion n 6) A DC machi machine ne commut commutato atorr is cleane cleaned d using using a. Paraffin b. b. Lead Lead free free petr petrol ol c. An abr abras asiv ivee mate materi rial al 7) The expected expected brush brush spring spring tension tension on a 6 kW DC generato generatorr would would be a. 28 to to 36 36 gra grams b. 28 to to 36 36 Kg c. 28 to to 36 36 ou ounces 8) Excessi Excessive ve brush brush arcin arcing g is caused caused by? by? a. Low Low bru brush sh spri spring ng tens tensio ion n b. Positi Positioni oning ng the the brush brushes es on on the the MNA MNA c. Fitt Fittin ing g of inte interp rpol oles es 9) A DC DC shu shunt nt moto motorr has has a. High High arm armat atur uree resi resist stanc ancee b. Low Low star starti ting ng torq torque ue c. High High sta start rtin ing g torq torque ue
10) DC generators generators are rated in a. Horsepower b. kVA c. Watts 11) To decrease the RPM of a DC DC shunt motor a. Fiel Field d resis resista tanc ncee is incre increas ased ed b. Field Field resist resistanc ancee is is decr decreas eased ed c. Arma Armatu ture re curr current ent is is incr increa ease sed d 12) Rotational speed of a DC motor is controlled by a. The The fie field ld resi resist stan ance ce onl only y b. The armatu armature re resist resistance ance only only c. Eith Either er of the the abo above ve 13) The expected speed range of a DC generator is is a. 5000 5000 to 800 8000 0 RPM RPM b. b. 1000 1000 to 2000 2000 RPM RPM c. 1800 18000 0 to to 200 20000 00 RPM 14) When the battery voltage is higher than the charger voltage a. The charge chargerr will will charge charge the batter battery y b. No current current will will flow betwee between n the charger charger and the battery battery c. The batte battery ry will will disch discharg argee throug through h the charg charger er 15) The Ni/Cad battery capacity test test is carried out a. Ever Every y 3 mont onths b. Only when the the battery battery fails fails to maintain maintain its its charge charge c. At the the per perio iods ds sta state ted d in the the AMS AMS 16) A frequency wild generator a. Is alw alway ayss used used as as a DC gener generat ator or b. Has a vari variabl ablee freque frequency ncy output output c. Mainta Maintains ins const constant ant RPM RPM but has has variabl variablee frequen frequency cy 17) RPM of a DC generator generator is a. Almost Almost const constant ant at at any aircr aircraft aft/en /engin ginee speed b. Relevan Relevantt to to the the airc aircraf raftt spee speed d c. Rela Relate ted d to to engin enginee spe speed ed 18) The Ni/Cad battery battery a. Requires Requires an approved approved modificat modification ion to replace replace a lead lead acid battery battery b. Is a direc directt replac replaceme ement nt for a lead lead acid acid batte battery ry c. Can repla replace ce a lead lead acid batt battery ery at at same same capacit capacity y
10) DC generators generators are rated in a. Horsepower b. kVA c. Watts 11) To decrease the RPM of a DC DC shunt motor a. Fiel Field d resis resista tanc ncee is incre increas ased ed b. Field Field resist resistanc ancee is is decr decreas eased ed c. Arma Armatu ture re curr current ent is is incr increa ease sed d 12) Rotational speed of a DC motor is controlled by a. The The fie field ld resi resist stan ance ce onl only y b. The armatu armature re resist resistance ance only only c. Eith Either er of the the abo above ve 13) The expected speed range of a DC generator is is a. 5000 5000 to 800 8000 0 RPM RPM b. b. 1000 1000 to 2000 2000 RPM RPM c. 1800 18000 0 to to 200 20000 00 RPM 14) When the battery voltage is higher than the charger voltage a. The charge chargerr will will charge charge the batter battery y b. No current current will will flow betwee between n the charger charger and the battery battery c. The batte battery ry will will disch discharg argee throug through h the charg charger er 15) The Ni/Cad battery capacity test test is carried out a. Ever Every y 3 mont onths b. Only when the the battery battery fails fails to maintain maintain its its charge charge c. At the the per perio iods ds sta state ted d in the the AMS AMS 16) A frequency wild generator a. Is alw alway ayss used used as as a DC gener generat ator or b. Has a vari variabl ablee freque frequency ncy output output c. Mainta Maintains ins const constant ant RPM RPM but has has variabl variablee frequen frequency cy 17) RPM of a DC generator generator is a. Almost Almost const constant ant at at any aircr aircraft aft/en /engin ginee speed b. Relevan Relevantt to to the the airc aircraf raftt spee speed d c. Rela Relate ted d to to engin enginee spe speed ed 18) The Ni/Cad battery battery a. Requires Requires an approved approved modificat modification ion to replace replace a lead lead acid battery battery b. Is a direc directt replac replaceme ement nt for a lead lead acid acid batte battery ry c. Can repla replace ce a lead lead acid batt battery ery at at same same capacit capacity y
19) The battery charger normally charges the battery with a. A cons consta tant nt volt voltag agee b. Either Either a curr current ent or or a const constant ant volt voltage age c. A cons consta tant nt curr curren entt 20) The minimum brush length is measured measured on a. The The shor shorte test st side side b. b. An aver averag agee is is tak taken en c. The The lon longe gest st side side 21) Constant speed AC generators generators are normally normally a. Exci Excite ted d by the the batt batter ery y bus-b bus-bar ar b. b. Self Self-e -exc xcit itin ing g c. Exci Excite ted d by by the the DC DC sup suppl ply y 22) As a lead acid cell discharges its relative density a. Increase b. b. Rema Remain inss the the same same c. Decrease 23) The relative density of a discharged lead acid battery is a. 1.150 b. 1.200 c. 1.260 24) The nominal voltage of a charged lead acid cell cell a . 1 .8 V b . 2 .2 V c . 2 .0 V 25) Increasing the cell plate area will a. Incr Increa ease se the the cur curre rent nt b. Incr Increa ease se the the volta voltage ge c. Incr Increa ease se the the cap capac acit ity y 26) In an AC generator generator a. The movi moving ng part part is is terme termed d the armatu armature re b. The movi moving ng part part is is terme termed d the rotor rotor c. The movi moving ng part part is term termed ed the the induct inductanc ancee coil 27) When frequency increases in an inductive inductive circuit the current flow will a. Increase b. b. Rema Remain inss the the same same c. Decrease
28) In an inductive circuit circuit the current a. Lags Lags the vol voltage age b. b. Lead Leadss the the volt voltag agee c. Is in pha phase se wit with h the the volt voltag agee 29) Apparent power is calculated calculated a. I sq squared x I b. V x I c. V squ squar ared ed divi divide ded d by by R 30) A motor clutch clutch is opened when a. The The mot motor or is swit switche ched d on on b. Rota Rotati tiona onall speed speed is is reduc reduced ed c. The The mot motor or is swit switche ched d off off 31) In a circuit with purely purely resistive loads a. Volt Voltag agee lead leadss curr curren entt b. Voltag Voltagee and and curr current ent are in phase phase c. Volt Voltag agee lags lags cur curre rent nt 32) In an inductive inductive circuit a. Volt Voltag agee and cur curre rent nt are are in phas phasee b. Curr Curren entt lea leads ds volta voltage ge c. Volt Voltag agee lead leadss curr curren entt 33) In capacitive capacitive circuit a. Volt Voltag agee lags lags beh behin ind d curr curren entt b. Volt Voltag agee lea leads ds curre current nt c. Curren Currentt is in phase phase with with the the volt voltage age 34) If a circuit has a power factor of 0 it will contain a. Resi Resist stan ance ce onl only y b. b. Indu Induct ctan ance ce only only c. Resi Resist stan ance ce and and ind induct uctan ance ce 35) Any electric motor is protected against sudden loads by a. A brake b. b. An enga engage ge clut clutch ch c. A mech mechani anical cal torq torque ue lim limit iter er 36) Damage to the system and motor motor can be caused by a. An open open cir circu cuit it break break coil coil b. Incorr Incorrect ectly ly set set limi limitt switc switches hes c. An open open cir circu cuit it clu clutc tch h coil coil
37) To calculate power factor a. Apparent power divided by true power b. Apparent power multiplied by true power c. True power divided by apparent power 38) The back EMF produced by an inductance depends on a. The inductance and the rate of change of the current b. The inductance of the indicator and the current flowing in it c. The inverse of the inductance and the size of the current 39) The vent of a lead acid battery cell is a. Sealed b. Leak proof c. Completely open 40) The electrolyte in a lead acid cell is a. A sulphuric acid b. A caustic acid c. A solution of sulphuric acid 41) An autotransformer has a. Two windings b. One wining c. Three windings 42) What happens to a thermistor with an increase of temperature a. Resistance increases b. Resistance remains constant c. Resistance decreases 43) A transformer has a turn ratio of 10 to 1 and a load impedance of 5 Ohms what is the input impedance? a. 500 Ohms b. 50 Ohms c. 20 Ohms 44) A current transformer when disconnected from a circuit must be a. Left open circuit b. Short circuited c. Have a load resistor 45) Economy coils a. Give a time delay b. Allow high current to pass c. Allow a relay to be held in on a low current
46) Slugged relays a. Operate quickly b. Introduce a time delay into the circuiting switching c. Must always be used on heavy duty circuit 47) To obtain a supply of 24V 60AH connect two a. 24V 30AH batteries in series b. 12V 30AH batteries in series c. 24V 30AH batteries in parallel 48) A motor brake is applied when the motor a. Is switched on b. Is switched off c. Applies excessive torque 49) A millivolt drop test on a heavy duty contacter is carried out with the contacts a. Open b. Closed c. Closing 50) Millivolt drop test reads 150mV at 300A contact resistance is a. 50 milliOhms b. 50 Ohms c. 0.0005 Ohms 51) Slugged relays a. Operate quickly b. Introduce a time delay into the circuiting switching c. Must always be used on heavy duty circuit 52) To obtain a supply of 24V 60AH connect two a. 24V 30AH batteries in series b. 12V 30AH batteries in series c. 24V 30AH batteries in parallel 53) A motor brake is applied when the motor a. Is switched on b. Is switched off c. Applies excessive torque 54) A millivolt drop test on a heavy duty contacter is carried out with the contacts a. Open b. Closed c. Closing 55) Millivolt drop test reads 150mV at 300A contact resistance is
a. 50 milliOhms b. 50 Ohms c. 0.0005 Ohms 56) A lagging power factor may be improved by a. Increasing the inductivity b. Increasing the capacitance c. Increasing the resistance 57) Two in phase voltages may be represented by a. Direct values b. Added values c. Vector sums 58) An electrostatic voltmeter has? a. Low loading effect on circuit b. High loading effect on a circuit c. Medium loading effect on a circuit 59) A simple ohmmeter may be used to a. Measure continuity and all resistance values b. Measure continuity and unknown resistance values c. Unknown resistance values only 60) Before using a simple ohmmeter a. It must be calibrated b. The test leads should be checked for resistance c. The test leads should be shorted together and the indicator set to zero 61) A High pass filter will a. Allow frequencies below a certain value to pass b. Allow frequencies above a certain value to pass c. Allow frequencies within a range to pass 62) Faradays Law States that a. The magnitude of the EMF is directly proportional to the magnetic flux b. The magnitude of the EMF is indirectly proportional to the Rate of change of flux c. The magnitude of the EMF is directly proportional to the Rate of change of flux 63) Magnetic inclination is the least at a. The equator b. The poles c. The isoclines
64) The voltage rating of a capacitor is a. The min voltage required to change b. The max voltage can be constantly applied c. Normal operating voltage 65) The relative permeability of a capacitor is a. The permeability of the dielectric b. The permeability of dielectric in relation to dry c. The permeability of dielectric in relation to a vacuum 66) When measuring the phase and line voltages of a generator, it was found that line and phase voltages were equal. The generator is a. Star wound b. Delta wound c. Either delta or star wound 67) To change the direction of a 3-phase induction motor you would a. Swap all of the input connections b. Remove one of the input connections c. Swap two of the stator connections 68) In a capacitive circuit current a. Leads voltage b. Lags voltage c. Is in phase with voltage 69) In an inductive circuit current a. Voltage lags current b. Voltage leads current c. Is in phase with voltage 70) What is the phase difference in a circuit with 100v, drawing 0.5 amps, consuming 50 Watts a. 45˚ b. 60˚ c. 90˚ 71) How much power is dissipated or absorbed when Battery has 20 Volts and resistor has 4 ohms? a. 0.1 watt b. 100 watt c. 0.001 watt
72) A circuit has 200 Volts and R1 = 5 ohms and R2 = 4 ohms in series. What is the total current of the circuit? a. 108 A b. 40 A c. 22.2 A 73) A circuit has 200 Volts and R1 = 5 ohms and R2 = 4 ohms in series. What is the voltage drop across R2? a. 88.8 V b. 111.1 V c. 200 V 74) When the north pole of one magnet is placed near the south pole of another magnet a. They will repel each other b. They will attract each other c. 10 & 20 75) Which of the following is true about lines of magnetic force? a. They do not have direction b. They do not follow iron c. They always form complete loops 76) A material that allows a large amount of lines of force to go through it has a a. High reluctance b. High permeability c. Low flux density 77) The lines of force that surround a magnet are called a. Permeance b. Magnetic inductance c. Flux lines 78) When a piece of iron is inserted into the core of a coiled wire through which current is flowing, the iron becomes a(n) a. Electromagnet b. Generator c. Magnetic domain 79) A property similar to conductance in a basic DC circuit is called ........ in a magnetic field a. Reluctance b. Magnetic flux c. Permeance 80) In order to increase the amount of EMF in a wire being moved through a magnetic field, the
a. Strength of the magnetic field will have to decrease b. Length of the conductor will need to decrease c. Speed of conductor movement will need to increase 81) If you want to convert an AC generator into a CD generator, you will need a. Brushes and reluctance b. Commutator and brushes c. Brushes and a magnetic domain 82) Disregarding the number of turns in the coil and the current flow and electromagnet's strength can be increased greatly by adding a a. Residual magnetism b. Paramagnetic core c. Ferromagnetic core 83) The strength of an electromagnet is proportional to the number of turns of wire in the coil and the current flowing through the coil a. True b. False 84) Forming a loop in a wire having current flowing through it forms a simple a. Antenna b. Electromagnet c. Magnet 85) An excess of electrons at one end of a conductor and a deficiency of electrons at the other end creates a. Electromagnetic induction b. Power c. Potential difference 86) In a simple AC generator, which part of the generator rotates to produce the induced voltage? a. Permanent magnets b. Armature c. Slip rings 87) The stationary member of a brushless alternator which provides connections for the external load is called a a. Winding b. Rotor c. Stator
88) In a modern brushless AC generator, which part of the generator rotates to produce the induced voltage?
a. Armature b. Rotor c. Stator 89) AC is widely used because of its versatility a. False b. True 90) The output voltages of a three-phase alternator are separated by 120 degrees a. False, they are 90 degrees apart b. False c. True 91) In a simple AC generator, which part of the generator rotates to produce the induced voltage a. Permanent magnets b. Armature c. Slip rings 92) The stationary member of a brushless alternator which provides connections for the external load is called a a. Winding b. Rotor c. Stator 93) In a modern brushless AC generator, which part of the generator rotates to produce the induced voltage? a. Armature b. Rotor c. Stator 94) AC is widely used because of its versatility a. False b. True 95) The output voltages of a three-phase alternator are separated by 120 degrees a. False, they are 90 degrees apart b. False c. True 96) The unit of power is a. Ampere b. Watt c. Farad 97) The unit of electrical potential is a. Henry
b. Ampere c. Volt 98) One megohm is equal to a. 1,000,000 ohms b. 10,000 ohms c. 1,000 ohms 99) The unit that changes ac to dc is a. A transformer b. A rectifier c. An inverter 100) The unit that changes dc to ac is a. A transformer b. A rectifier c. An inverter 101) To find the current flowing in a dc circuit, the correct formula is a. I = R : E b. I = E : R c. E = I : R 102) If service no 1 is isolated from the supply shown there will be - three fuses circuit a. An increase in supply voltage b. A decrease in supply voltage c. A decrease in total current consumption 103) The reduction of the variable resistor R1 shown would - divider R1 and R2 in series a. Increase the total current drawn b. Not affect the total current drawn c. Decrease the total current drawn 104) Since electrical supplies taken from a bus bar are in parallel, isolating some of the services would a. Not affect the current consumption, it would reduce the voltage b. Reduce the current consumption from the bus bar c. Increase the current consumption from the bus bar 105) During circuit testing, an insulation resistance test a. Also indicates that continuity is satisfactory b. Should be carried out before a continuity test c. Should be carried out after a continuity test
106) When checking the bonding of a component which anodic ally treated against corrosion the a. Resistance of the anodic film is negligible and may be ignored b. Anodic film must be penetrated to ensure good contact of the test probes c. Resistance of the anodic film must be measured and taken into account during the test 107) Relative humidity has to be taken into account when conducting a. Replacement of items equipment b. Battery percentage capacity tests c. Wiring insulation resistance tests 108) The type of switch (exclusive OR) is a. Single pole change over b. Single throw, double pole c. Double pole change over 109) When resistors are in parallel a. The total resistance is larger than the smallest resistor b. The total resistance is smaller than the smallest resistor c. The total resistance is the sum of all resistors 110) When resistors are in parallel, the total current is equal to a. The reciprocal of all the currents b. The current across one resistor c. The sum of the currents 111) The voltage output of a generator is controlled by a. Varying the resistance of the output b. Varying the current of the field c. Varying the current of the output 112) When the generator field is supplied through the battery master switch, if the switch is selected off whilst the engine is running a. The generator will continue to produce since it is self sustaining b. The generator will only continue to produce power if the engine is above idle speed, since the generator is self sustaining c. The generator will be de-excited and hence, cease to produce power 113) A short circuit between the supply and earth a. Could be very dangerous as the current drawn will be very high b. Is not dangerous as the current drawn will be low c. Does not matter if the circuit uses the aircraft earth return
114) Two similar 12V batteries connected in parallel will produce
a. 24V emf with twice the capacity of each battery b. 12V emf with twice the capacity of each battery c. 24V emf with the same capacity of each battery 115) An increase in operating temperature in most electrical devices carrying current results in a. A decrease in resistance and increase in current b. Not affect on the resistance and current c. An increase in resistance and decrease in current 116) An increase in operating temperature in most electrical devices carrying current results in a. A decrease in resistance and increase in current b. An increase in resistance and decrease in current c. No effect on the resistance and current 117) A direct current of 12 mA flows through a circuit which has a resistance of 1,000 ohms. The power dissipated by the circuit is a. 12 mW b. 12 W c. 144 mW 118) A short circuit should be detected by the use of a. An insulation tester only b. A continuity tester c. A continuity tester or an insulator tester 119) The result of an insulation resistance test of an electrical cable a. Also indicate continuity of a cable b. May vary with the weather conditions under which the aircraft is tested c. Will always be infinity if the cable is correctly installed 120) If, in a simple electrical circuit, the power consuming devices are in parallel, the total current consumed is equal to the sum of the a. A decrease in resistance and increase in current. Currents taken by the devices divided by the number of devices b. Reciprocals of the currents taken by the devices c. Current taken by the devices 121) The 24 battery has an internal resistance of 1 ohm and the ammeter indicates 12 A. The value of the load resistor is a. 2 ohms b. 1 ohms c. 6 ohms
122) A flexible fuel pipe undergoing inspection after a period of service requires to be checked electrically a. For continuity of the integral bonding and insulation of the outer cover b. For insulation of the outer cover only c. For continuity of the integral bonding only 123) The position of a ratio meter pointer is determined by a. The opposing torques of the two coils relative to the permanent magnet field b. The opposing torques developed by both coils c. The torque of one coil relative to the permanent magnet field 124) A frequency wild generator is used for a. Instruments and navigation equipment b. Deicing load c. Any ac load 125) A soft iron core is used in electromagnets a. It has high permeability and high coercivity b. It has low permeability and high coercivity c. It has high permeability and low coercivity 126) One purpose of electrical bonding on aircraft is a. To isolate all components electrically and therefore make the static potential constant b. To safely dissipate local static charges and lightning strikes c. To prevent lightning strike damage 127) The various parts of an aircraft airframe are maintained at the same potential by a. Static discharge wicks b. The supply bus bars c. Bonding 128) The purpose of a circuit breaker in an electrical system is a. To break a particular circuit when an overload condition occurs b. To prevent the battery being discharged through the generator when the engine is stopped c. The torque of one coil relative to the permanent magnet field 129) The risk of a fire due to static electricity is overcome a. By fitting static wicks and insulating all metal components b. By connecting all metal component by bonding c. By fitting static wicks and isolating the battery from inflammable gas sources
130) A loss of electrical insulation results in a. An open circuit between the supply and earth b. An open circuit in the supply c. A short circuit between the supply and earth 131) The test equipment normally used to carry out conductivity test on an electrical cable is a. A high tension circuit tester b. A low reading ohmmeter c. An ammeter 132) An insulation resistance test using a megger will show up a. Both open and short circuit b. Open circuits only c. Short circuits only 133) When an electrical supply becomes open circuit a. The loss of continuity will prevent its component from functioning b. The fuse or circuit breaker should isolate the circuit due to the increased current drawn c. The component will operate normally, but will not switch off 134) When the GPU is connected to the aircraft a. It is a parallel with the aircraft generator b. It is not parallel with the aircraft generator c. It supplies essential services only 135) The term dry joint when applied to soldering is when a. The surfaces have been soldered without flux b. The penetration is complete, forming a water-tight joint c. The surfaces to be joint have not reached the required temperature 136) Inertia switches are primarily used in aircraft a. To indicate the aircraft is airborne b. For emergency circuit c. To operate a circuit after a time delay 137) If the aircraft structure is used for the earth. When fitting a battery a. The positive is connected to the earth b. Neither is connected to earth c. The negative is connected to earth 138) The minimum bend radius for cable loom is a. 8 times the loom diameter b. 2 times the loom diameter c. 5 times loom diameter
139) A static inverter is used to a. Convert frequency wild AC to DC b. Convert DC to AC c. Convert frequency regulated AC to DC 140) The purpose of the short pin on the electrical ground connector plug is a. To provide earth connection b. To provide a locking mechanism to prevent the plug falling out c. To give a supply for the ground power contactor 141) The purpose of the six pins on an AC ground connector plug is a. Four long pins for AC and two short pins for earth b. Four long pins for AC and two short pins for DC holding c. Four long pins for AC and two short pins for AC holding 142) When removing the ground power from an aircraft after starting engines a. The ground power unit will automatically stop on removal of the ground power plug b. Removal of the ground power plug always automatically transfers power to the aircraft system c. The ground power supply should be switched off before removing the ground power supply plug 143) A differential relay in a twin generator system will ensure a. That the generator voltages are nearly equal before parallel b. That one generator always comes on line before the other c. That only one generator can supply the bus bar at a time 144) What is the purpose of the permanent magnets in an alternator a. To control the frequency b. To provide initial excitation c. To rectify the current 145) Two magnets in attraction. The force would be a. Proportional to the air gap b. Inversely proportional to the air gap c. Inversely proportional to squared of the air gap 146) The purpose of the six pins on an AC ground connector plug is a. Four long pins for AC and two short pins for earth b. Four long pins for AC and two short pins for DC holding c. Four long pins for AC and two short pins for AC holding 147) When removing the ground power from an aircraft after starting engines a. The ground power unit will automatically stop on removal of the ground power plug
b. Removal of the ground power plug always automatically transfers power to the aircraft system c. The ground power supply should be switched off before removing the ground power supply plug 148) A differential relay in a twin generator system will ensure a. That the generator voltages are nearly equal before parallel b. That one generator always comes on line before the other c. That only one generator can supply the bus bar at a time 149) What is the purpose of the permanent magnets in an alternator a. To control the frequency b. To provide initial excitation c. To rectify the current 150) Two magnets in attraction. The force would be a. Proportional to the air gap b. Inversely proportional to the air gap c. Inversely proportional to squared of the air gap 151) What effects the frequency in a generator a. The armature diameter b. The speed c. The resistance of the windings 152) Should alternator or generator failure occur in flight, to conserve battery power a. Its rate of discharge should be slowed by using high resistance loads only b. The battery should be discharged at a rate which corresponds to its ampere hour rating c. Load shedding should be carried out by switching off the non essential loads 153) When the generator field is supplied through the battery master switch, if the switch is selected off whilst the engine is running a. The generator will be de-excited and hence cease producing power b. The generator will continue to produce power since it is self-sustaining c. The generator will only continue to produce power if the engine is above idle since the generator is then self-sustaining 154) A generator cut-out is provided to a. Allow the generator to be isolated in a crash b. Prevent discharge of the battery through the generator c. Prevent the battery from being overcharged
155) A positive ammeter reading indicates that a. The bus-bar is being supplied by the generator b. The battery is being charged by the generator and there is no supply for the bus bar c. The bus-bar is being supplied by the generator 156) Immediately after starting, with no other electrical service switched on, the ammeter shows high ampere charge to the battery a. This indicates a generator failure so the engine must be shut down immediately b. This may be normal and is only a cause for concern if the high charge rate persists c. This indicates a battery failure since there should be on immediate charge so the engine must be shut down immediately 157) The electrolyte in a nickel cadmium cell is a. Hydrogen peroxide b. Calcium carbonate c. Potassium hydroxide 158) The correct way to determine the state of charge of a nickel cadmium battery is a. By a complete and measured discharge b. By checking the specific gravity of each cell c. By checking the voltage of each cell under load 159) If a nickel cadmium aircraft battery is not required for immediate service, it should be stored a. In the fully charged condition b. In the full discharged condition c. In a totally dry condition 160) If a nickel cadmium battery overheats, it is an indication of a. The generator voltage regulator setting is too low b. The generator is not connected to the bus bar c. Thermal runway 161) When checking a nickel cadmium battery, in situ, for serviceability a. A hydrometer must be used b. A load is applied to the battery and the voltmeter reading noted c. The electrical circuits must be isolated before installing shorting strips 162) When using ac power on the bus bar you require 28V DC for battery charging a. An AC inverter would be required b. A DC transformer and rectifier would be required c. A AC transformer and rectifier would be required
163) For battery charging the electrical supply connected to the battery must be a. DC b. AC at 50 cps c. AC at 400cps 164) As an installed battery becomes fully charged by the aircraft generator a. The generator voltage decreases to supply the steadily decreasing current b. The battery voltage nears its normal level so the charging current decreases c. The battery contactor isolates the battery from the generator 165) A battery which is assumed to be 100% efficient and to have a capacity of 60 amps-hours at the 10 hour rate will deliver a. 60 amps for 10 hours or 6 amps for 10 hours, depending upon the rate of demand b. 60 amps for 10 hours c. 6 amps for 10 hours 166) Spillage from a lead acid battery may be neutralized by a. Applying a coating of Vaseline b. Washing with a dilute solution of sodium carbonate c. Washing with distilled water 167) The specific gravity of the electrolyte in a lead acid battery a. Remains substantially constant regardless of the state of charge and is not therefore a guide to a state of charge b. Remains constant with changes in the state of charge but is a useful guide to the amount of acid contained in electrolyte c. Changes with the state of charge and is therefore a measure of the state of charge 168) Before taking SG readings of a lead acid battery recently removed from an aircraft a. The electrolyte temperature must be noted b. A period of 1 hour should have elapsed to allow the SG to stabilize c. The battery must be charged at the 10 hour rate for one hour 169) To prevent corrosion at the terminals of a lead acid battery a. Copper connectors are used b. Petroleum jelly may be applied to the connections c. The connections may be painted 170) A lead acid battery is considered to be fully charged when the a. SG reaches 1.180 b. Cells begin to gas c. SG and voltage remain constant for a specified period
171) When checking the specific gravity of the electrolyte in a battery a. One cell only need be checked as the remainder will read the same b. Each cell should be checked as the reading may differ c. Only the end cells need to be checked as they contain the terminals 172) To restore the level of electrolyte which has been lost due to normal gassing during battery charging a. Sulphuric acid must be added b. Electrolyte of the same specified gravity as that contained in the battery must be added c. Distilled water must be added 173) In the procedure to be followed after spillage of battery acid, neutralizing may be carried out a. With a dilute solution of sodium carbonate b. By washing with distilled water c. By applying a coating of petroleum jelly 174) A 12 Volt lead acid battery has a. 12 cells b. 6 cells c. 24 cells 175) The electrolyte in a lead-acid battery contains a. Nitric acid b. Hydrochloric acid c. Sulphuric acid 176) When checking the specific gravity of the electrolyte in a battery a. One cell only need be checked as the remainder will read the same b. Each cell should be checked as the reading may differ c. Only the end cells need to be checked as they contain the terminals 177) To restore the level of electrolyte which has been lost due to normal gassing during battery charging a. Sulphuric acid must be added b. Electrolyte of the same specified gravity as that contained in the battery must be added c. Distilled water must be added 178) In the procedure to be followed after spillage of battery acid, neutralizing may be carried out a. With a dilute solution of sodium carbonate b. By washing with distilled water c. By applying a coating of petroleum jelly
179) A 12 Volt lead acid battery has a. 12 cells b. 6 cells c. 24 cells 180) The electrolyte in a lead-acid battery contains a. Nitric acid b. Hydrochloric acid c. Sulphuric acid 181) Which of the following statements is true? a. A thermocouple operates on the principle of changing resistance proportional to applied b. A thermocouple operates on the principle of potential difference between two dissimilar metals c. A thermocouple operates like a potentiometer 182) In an EGT temperature system, the ........ junction is the thermocouple and the ......... junction is the indicator a. Hot & hottest b. Cold & hot c. Hot & cold 183) When heated chromel and alumel develop ........... and ........... potentials respectively a. Positive & negative b. Negative & positive c. Hot & cold 184) A special type of sensing element with properties which allow it to produce large resistance changes for small temperature changes is a a. Thermocouple b. Thermistor c. Photo cell 185) Thermistors normally have a ............ temperature coefficient a. Constant b. Positive c. Negative 186) The unknown resistance under test when using a multimeter is measured based upon known a. Current b. Voltage c. Inductance
187) The known voltage applied to a resistance under test when using an ohmmeter, originates from a/an a. 60 Hz battery b. External battery c. Internal battery 188) The resistance connected in series with the circuits and in parallel with the meter movement when using an ammeter is called a/an a. Shunt b. Resistive inductor c. Inductive resistor 189) A megger is used to measure extremely .......... values of resistance a. Low b. High c. Negative 190) A meter which is extremely accurate in resistance readings is the a. Multimeter b. Megger c. Wheatstone bridge 191) If an RCCB opens due to an over current detection, its remote trip reset C/B will not open. a. True b. False 192) Pulling the remote trip reset C/B will cause the RCCB to a. Remain in the same position b. Close c. Open 193) D'arsonval and taut band meter movements deflect to a reading due to a. Current flow in their coil b. The counter EMF c. A difference in voltage potential 194) The effect a voltmeter has on a circuit when connected into that circuit for testing is called a. Shunting b. Loading c. Balancing
195) Sensitivity of a voltmeter is expressed in a. Volts per ohm b. Ohms per amp c. Ohms per volt 196) The higher the gauge number, the .................. the wire diameter. a. Larger b. Smaller c. Longer 197) PVC insulated wiring is no longer used due to its flammability and production of toxic gases, which are corrosive, during combustion. a. False b. True 198) A fuse is wired in parallel with the circuit load a. False b. True 199) The term ............ as applied to circuit breakers, means the breaker cannot be reset as long as the overload condition exists. a. Trouble-free b. Trip-free c. Won’t reset 200) Reed switch contacts open or close as a function of being placed in close proximity to a a. Fluid substance b. Electrical source c. Magnetic field 201) A capacitor used in a split-phase motor usually creates a phase shift in the start windings a. False b. True 202) How may the direction of a DC motor be changed? a. Add a shunt resistor b. Adding a capacitors c. Swap polarity of applied voltage 203) What is the primary advantage of a shunt wound motor? a. Constant speed b. Low starting torque c. High starting torque
204) What are the characteristics of a compound wound motor? a. Has series characteristics b. Both answers are correct c. Has shunt characteristics 205) In a DC motor the voltage induced in the windings as its armature rotates is called a. Induced current b. Induced EMF c. Counter EMF 206) The advantages of an autotransformer are all except which of the following? a. Fewer turns of wire b. More eddy current c. Less power loss 207) What type device is most widely used in electronic circuits to match impedance a. Hysteresis b. Transformer c. Capacitors 208) What are the advantages of AC motors? a. Less expensive, can be made brushless b. Less expensive, always uses brushes c. Shaded pole, high starting torque 209) What two factors determine speed in an AC motor? a. Number of poles, frequency of output voltage b. Number of poles, frequency of applied voltage c. Counter EMF, number of poles 210) The applied voltage frequency in an induction motor produces what is known as: a. Operating efficiency b. Modulating speed c. Synchronous speed 211) If the power output of a transformer is 160 watts, and the power input is 200 watt, the efficiency is ....... percent. a. 84 b. 80 c. 125 212) If the coefficient of coupling is about one, and the power of the primary winding of a transformer is 40 watt, the power in the secondary winding is ..... Watts. a. 20 b. 80 c. 40
213) Voltage induced in the core of transformers cause current to flow in the core. The current is called a. Eddy current b. Core current c. High frequency losses 214) Eddy currents may be reduced by laminating the core material a. False b. True 215) The primary and the secondary windings of an autotransformer are wound on the same core. a. False b. True 216) Power factor is normally expressed as a percentage. In theory, when voltage and current are exactly in phase. The power factor will be a. Less than 100% b. 100% c. more than 100% 217) In an AC circuit, the product of E x I is known as a. Inductive reactance b. True power c. Apparent power 218) Apparent power is always greater than true power a. True b. False 219) If there are 1200 turns in the primary winding and 300 turns in the secondary winding of a transformer, and the voltage across the primary winding is 100 V, the secondary winding is ....... volts. a. 400 b. 25 c. 12 220) A transformer has a primary winding with 1000 turns and a secondary winding with 250 turns. If the current in the primary winding is 0.4 A, the current in the secondary winding is ...... A. a. 0.10 b. 0.80 c. 1.60
221) Which of the following statements is true regarding the charging of a capacitor? a. Electrons flow through the dielectric b. Electrons can flow onto a plate c. Electrons can be stored in the dielectric 222) An increase in frequency will have what effect on inductive and capacitive reactance? a. Inductive reactance goes unchanged. Capacitive reactance decreases b. Inductive reactant decreases. Capacitive reactance increases c. Capacitive reactance decreases. Inductive reactance increases 223) What is the total opposition to the current flow in a circuit having reactance at a given frequency? a. Impedance b. Resistance c. Inductance 224) In a purely resistive circuit the relationship of voltage to current is said to be in phase. a. False b. True 225) To calculate the power factor a. 0.707 x true power b. Apparent power / true power c. True power / apparent power 226) The amount of inductance produced in a coil decreases if the a. Number of turns is increased b. Diameter of the coil is decreased c. Space between the turns is decreased 227) The amount of inductance produced in a circuit can be changed if the circuit contains a ...... inductor. a. Variable b. Air core c. Iron core 228) Which of the following statements is true regarding current and voltage in a circuit containing and inductor? a. When current begins to flow, it will gradually increase to a maximum voltage b. There is no counter EMF when the current first begins to flow c. The voltage across the inductor will be zero volts all times
229) A very thin oxide film is used as the dielectric in a(n) ....... capacitor a. Mica b. Electrolytic c. Dielectric 230) A capacitor that is polarized (negative and positive leads) is called a(n) ...... capacitor a. Paper b. Ceramic c. Electrolytic 231) The amount of inductance produced in a coil decreases if the a. Number of turns is increased b. Diameter of the coil is decreased c. Space between the turns is decreased 232) A multiple phase alternator with a single-phase output of 115 V will have a phaseto-phase output of 230 V a. It varies b. True c. False 233) A three phase alternator has its A, B, C output phases marked respectively a. T1 , T2 , T3 b. A1 , B1 , C1 c. T4 , T5 , T6 234) Which of the following is a unit of inductance? a. Ohm b. Milihenry c. Hertz 235) The voltage induced in an inductor as a result of a current change is called a. Dissipated power b. Impedance c. Counter EMF 236) A three-phase alternator with a single-phase output of 115 V will have a phase-to phase output of a. 0.707 x 115 V b. 1.414 x 115 V c. 2 x 115 V
237) A multiple phase alternator with a single-phase output of 115 V will have a phaseto-phase output of 230 V a. It varies b. True c. False 238) A three phase alternator has its A, B, C output phases marked respectively a. T1 , T2 , T3 b. A1 , B1 , C1 c. T4 , T5 , T6 239) Which of the following is a unit of inductance? a. Ohm b. Milihenry c. Hertz 240) The voltage induced in an inductor as a result of a current change is called a. Dissipated power b. Impedance c. Counter EMF
241) a. A low pass fitter b. A high pass fitter c. An integrator 242) The right diagram represents a. A differentiator b. A high pass filter c. Low pass filter 243) _____________ can pass a low pass filter. a. Lower frequencies b. Higher frequencies c. Medium frequencies
244) _____________ can pass a high pass filter. a. Lower frequencies
241)
The left diagram represents
b. Higher frequencies c. Medium frequencies 245) For a middle-frequency speaker a ____________ filter is used a. Low pass b. High pass c. Band-pass
246) The left diagram represents a. A low pass filter b. A differentiator c. An integrator 247) The right diagram represents a. A high pass filter b. A differentiator c. An intergrator 248) An Integrator at high frequency a. The capacitor has insufficient time to charge up b. The capacitor voltage is high c. Input voltage is much less than across the resistor 249) A differentiator at low frequency a. The capacitor has no time to charge up b. The capacitor has time to charge up c. Voltage across the capacitor is much less than the source voltage 250) An Integrator at high frequency a. The capacitor voltage is high b. Input voltage is much less than across the resistor c. Input voltage equals voltage across the resistor
(For question no. 251 – 260 please refer to this diagram) 251) The 3 Ohm and 12 ohm resistors can be replaced by one a. 9 Ohm resistor b. 15 Ohm resistor c. 36 Ohm resistor 252) The 3 Ohm ,12 ohm and 30 Ohm resistors can be replaced by one a. 15 Ohm resistor b. 45 Ohm resistor c. 10 Ohm resistor 253) The resistor of Quiz 2 and the 24 Ohm resistor can be replaced by a. 7 Ohm resistor b. 13 Ohm resistor c. 17 Ohm resistor 254) By knowing answer 3, what is the total resistance a. 6 ohms b. 17 ohms c. 12 ohms 255) By knowing answer 4, what is the total power a. 17 Watts b. approximately 6 Amperes c. 9/17 Watts 256) By Knowing that the total resistance is 17 Ohms the total current is a. 17/3 A b. 3/17 A c. 3 x 17 A 257) By knowing the total current, how much current flows through the 10 Ohm resistor a. More b. Less c. The same 258) The voltage drop on the 10 Ohm resistor is _________ as all the remaining resistors.
a. Higher b. Lower c. The same 259) The 10 Ohm resistor has a colour code with 10% tolerance a. Brown, black, black, gold b. Brown, black, black, silver c. Black, brown, black, silver 260) The 24 Ohm resistor has a colour code with a tolerance of 20% a. Red, orange, black b. Red, yellow, black, gold c. Red, yellow, black 261) A resistor with 49 Kilo Ohms and 20% tolerance following colours a. Yellow, red, orange & silver for tolerance b. Yellow, red, orange & no band for 20& tolerance c. Orange, yellow, red & no band for 20% tolerance 262) A resistor with 5,6 Mega Ohms and 20% tolerance following colours a. Yellow, green, yellow b. Blue, violet, blue c. Green, blue, green 263) A resistor with orange, gray, yellow & gold colour bands has a. 380 Kilo Ohms & 5% tolerance b. 27 Kilo Ohms & 5% tolerance c. 380 Kilo Ohms & 15% tolerance 264) A resistor with blue, gray, red & silver colour bands has a. 6800 Ohms & 5% tolerance b. 6800 Ohms & 10% tolerance c. 680 Ohms & 5% tolerance 265) A resistor with brown, black, red colour bands has a. 10 kilo Ohm and 20% tolerance b. 100 Ohm and 10% tolerance c. 1 kilo Ohm and 20% tolerance 266) A capacitor with 120 pF and plus/minus 20% tolerance following colours a. Brown, red, brown b. Brown, red, brown & black band for plus/minus 20% tolerance c. Brown, yellow, brown & black band for plus/minus 20% toleranc 267) A capacitor with 4 red bands has following values a. 2.2 nF & plus/minus 10% tolerance
b. 2.2 nF & plus/minus 5% tolerance c. 2200 pF & plus/minus 2% tolerance 268) A capacitor with orange, gray, yellow & brown colour bands has a. 380 nF & plus/minus 1% tolerance b. 380 pF & plus/minus 1% tolerance c. 380 nF & plus/minus 2% tolerance 269) A capacitor with blue, gray, red & silver colour bands has a. 6800 pF & plus/minus 5% tolerance b. 6800 pF & plus/minus 10% tolerance c. 680 pF & 10% tolerance 270) A capacitor with brown, black, red & gold colour bands has a. 10 pF & plus/minus 20% tolerance b. 100 pF & plus/minus 10% tolerance c. 1000 pF & plus/minus 5% tolerance 271) In an inductive circuit a. Current leads voltage b. Voltage leads current c. Current is equal voltage 272) In a capacitive circuit a. Voltage is at the same time as current b. Voltage leads current c. Current leads voltages 273) The power factor is calculated Voltage x Current x __________ a. Cosinus of phase angle b. Sinus of phase angle c. Tangens of phase angle 274) The power factor is a. Apparent power/true power b. True power/apparent power c. Volt x Amps x sin theta 275) A series wound motor has a. Constant rpm b. Low torque c. High torque
276) In a 3 phase motor, the fileld windings are a. 30˚ apart
b. 120˚ apart c. 200˚ apart 277) A standard auto-transformer has a. Separate primary and secondary windings b. Two windings c. One winding 278) For motors use Flemmings a. LH Rule b. RH Rule c. Power rule 279) The formula of "inductive reactance" XL is a. XL = 1 / 2 pi f L b. XL = 2 pi f L c. XL = omega f L 280) The formula for "Capacitive Reactance" Xc is a. Xc = 2 pi f C b. Xc = omega f C c. Xc = 1 / 2 pi f C 281) The value of AC that has the same heating effect as DC is called a. Average = 0.637 of peak V b. RMS = 0.707 of peak V c. RMS = square root 2 of peak V 282) Capacitors are often named by their dielectric. Which capacitor is polarity sensitive? a. Oil b. Grease/ ceramics c. Electrolytic 283) Capacitors in series. Which formula is correct a. CT = C1 x C2/C1 + C2 b. CT = C1 + C2/C1 x C2 c. CT = C1 + C2 284) Capacitors in parallel. Which formula is correct a. CT = C1 x C2/C1 + C2 b. CT = C1 + C2 c. CT = C1 + C2/C1 x C2 285) Capacitors in series. Which formula is correct a. CT = C1 + C2 + C3/C1 x C2 x C3
b. CT = C1 + C2 + C3 c. 1/CT = 1/C1 + 1/C2 + 1/C3 286) The dielectric constant of air is a. Pi/2 b. 1 c. Square root of 2 287) Mica, paper and ceramic capacitors are made for ranges from 200 - 400 Volts. Oil capacitors for up to a. 1,000 Volts b. 2,500 Volts c. 7,500 Volts 288) Inductors in parallel. Which formula is correct a. LT = L1 x L2/L1 + L2 b. LT = L1 + L2/L1 x L2 c. LT = L1 + L2 289) Inductors in series. Which formula is correct a. LT = L1 x L2/L1 + L2 b. LT = L1 + L2 c. LT = L1 + L2/L1 x L2 290) Inductors in parallel. Which formula is correct a. LT = L1 + L2 + L3/L1 x L2 x L3 b. LT = L1 + L2 + L3 c. 1/LT = 1/L1 + 1/L2 + 1/L3 291) An induced electric current always flows in such a direction that it opposes the change producing it. a. Is Kirchoff’s law b. Is Lenz’s law c. Is Maxwell’s law 292) The algebraic sum of the currents flowing through all the wires in a network that meet at a point zero a. Is stated in Gaus’ current law b. Is stated in Lenz’s current law c. Is stated in Kirchoff’s current law
293) The algebraic sum of the e.m.fs within a closed circuit is equal to the sum of the products of the current and the resistances in the various portions of the circuits.
a. Is stated in Kirchoff’s voltage law b. Is stated in Henry’s voltage law c. Is stated in Lenz’s voltage law 294) In a 3 phase AC system the phase to phase voltage is a. Line voltage x square root of 2 b. Line voltage x square root of 3 c. Line voltage x pi/2 295) In a three phase AC system: Line Voltage is between a. Two phases b. Plus and ground c. One phase and the star point 296) In a brushless 3 phase AC motor, the armature is a. Delta wound b. Star wound c. Star or delta wound 297) A variable resistor with three terminals is a a. Thyristor b. Rheostat c. Potentiometer 298) A PRIMARY CELL a. Cannot be recharged b. Can be recharged c. Needs a trickle charger 299) A SECONDARY CELL a. Cannot be recharged b. Can be recharged c. Needs a trickle charger 300) Resonance in a resonant circuit occurs mostly at a. Omega L = omega C b. 2 pi f C = 2 pi f L c. omega L = 1/ omega C 301) For how many hours will a 140AH battery deliver 15A? a. 21 b. 9h and 20 min c. 9h and 33 min 302) What frequency is used in aircrafts a. 50 Hz
b. 60 Hz c. 400 Hz 303) AC current measured in terms of DC that produces the same heating effect is a. Effective AC b. Peak AC c. Average AC 304) Effective AC = a. 1.36 x peak b. 0.707 x peak value c. 1.414 x peak 305) Peak of 115V AC is a. 81.3 V b. 200 V c. 162.6 V 306) What is true power measured in ___________ and is Volts x Amps x Power Factor a. VA b. Watt c. VAcos 307) What does the power factor equal in a purely resistive circuit? a. Pi/2 b. Pi c. one 308) What is the purpose of laminating the poles of a DC Generator a. To prevent eddy currents b. To make the motor lighter c. For better cooling 309) An induced electric current always flows in such a direction that it opposes the change producing it. a. Is Kirchoff’s law b. Is Lenz’s law c. Is Henry’s law 310) What does the charge of a capacitor not depend on? a. Distance between plates and area of plates b. Dielectric c. Amount of current flow 311) What is the advantage of the use of AC power in aircrafts? a. Higher voltage
b. AC can be transformed c. AC is more reliable 312) What is the residual Voltage result of? a. Stored electrons b. Residual resistance c. Residual magnetism 313) What is damaged by prolonged sparking in a CD Generator? a. The commutator b. The field c. The stator 314) An auto transformer has a. 3 coils b. 1 coils c. 2 coils 315) What does a narrow Hysteresis loop signify? a. Small distance between plates b. Much hysteresis c. Approach of ideal = no hysteresis 316) A shunt is used to ___________ the range of an ammeter a. Decrease b. Increase c. Stabilize 317) What is the purpose of the Capacitor in the starting circuit of a 2 phase inductive motor? a. To reduce inductive load b. For noise suppression c. To create an artificial rotating field 318) The word C I V I L is a way to remember relation ship of a. Capacitors and inductors b. Diodes and transistors c. AC motors 319) The opposition to the flow of electrons offered by a device or material is a. Reluctance b. Resistance c. Romance 320) What does a fat Hysteresis loop signify? a. Small distance between plates
b. Approach of ideal = no hysteresis c. Much hysteresis 321) Voltage coils are made of a. Thick short copper wire b. Fine long copper wire c. Low resistance steel wire 322) Current coils are made of a. Low resistance steel wire b. Fine long copper wire c. Thick short copper wire 323) Interpoles and Compensating windings are used to a. Reduce armature reaction b. Increase armature reaction c. To move the position of the brushes 324) Passive Filters consist of a. Capacitors and inductors b. Capacitors and reactors c. Inductors and reactors 325) A shaded pole single phase induction motor consists of projecting pole pieces and a. Squirrel cage b. A capacitor c. A surrounding copper strap 326) At Resonant frequency, when XL=XC in a series circuit Z is a. At maximum and current I at minimum b. At minimum and current I at maximum c. Any value between maximum and minimum 327) At Resonant frequency, when XL=XC in a parallel circuit Z is a. Any value between maximum and minimum b. At minimum and current I at maximum c. At maximum and current I at minimum 328) Calculate Z if R=6 Ohm, XL = 58 Ohm and XC = 50 Ohm a. 10 ohm b. 12 ohm c. 1 ohm
329) The formula for Z in question 3 is a. Z = V / I
b. Z = sqrt(R² + (XL - Xc)² c. Z = R² / XL + Xc 330) On a step down transformer the primary side a. Higher gauge wire b. Has less windings c. Has more windings 331) The electrolyte in a so called dry cell consists of a. Potassium hydroxide b. Ammonia chloride and zinc chloride c. Sulphuric acid 332) An Ammeter in a battery charging circuit indicates a. C b. – c. + 333) When an ammeter is connected in parallel to the power source a. It creates a short circuit b. It reads current c. It does not have an effect on the instrument 334) What method of Battery Charging is used to keep the battery fully charged a. Constant current charging b. Trickle charging c. Constant voltage charging 335) Thermal runaway of a NiCad Battery starts with excessive gassing and ends with destruction, caused by a. Too low ambient temperature b. Heavy discharge c. Heat reduced resistance and high current flow 336) A high pass filter can be used to: a. Prevent interference to AM broadcast reception b. Prevent interference to TV reception c. Pass a band of speech frequencies in a modular 337) A high pass filter attenuates: a. High frequencies but not low frequencies b. All except a band of VHF frequencies c. Low frequencies but not high frequencies 338) The following unit in a DC power supply performs a rectifying operation: a. A full-wave diode bridge
b. An electrolytic capacitor c. A fuse 339) A low-pass filter is used in the antenna lead from a transmitter: a. To eliminate chirp in CW transmission b. To reduce radiation of harmonics c. To increase harmonic radiation 340) A communication receiver may have several IF filters of different bandwidths. The operator selects one to: a. Improve the receiver sensitivity b. Increase the noise received c. Improve the reception of different types of signal 341) Television interference caused by harmonics radiated from an amateur transmitter could be eliminated by fitting: a. A high pass filter b. A low pass filter in the transmitter output c. An active filter 342) A high pass RF filter would normally be fitted: a. Between microphone and speech amplifier b. Between transmitter output feedline c. At the antenna terminals of a TV receiver 343) A band stop filter will: a. Pass frequencies each side of a band b. Stop frequencies each side of a band c. Only allow one spot frequency through 344) A low pass filter for a high frequency transmitter output would: a. Attenuate frequencies below 30 MHz b. Attenuate frequencies above 30 MHz c. Pass audio frequencies above 3 kHz 345) Installing a low pass filter between the transmitter and transmission line will: a. Ensure an SWR not exceeding 2:1 b. Permit higher frequency signals to pass to the antenna c. Permit lower frequency signals to pass to the antenna
346) Television interference caused by harmonics radiated from an amateur transmitter could be eliminated by fitting: a. A high pass filter
b. A low pass filter in the transmitter output c. An active filter 347) A high pass RF filter would normally be fitted: a. Between microphone and speech amplifier b. Between transmitter output feedline c. At the antenna terminals of a TV receiver 348) A band stop filter will: a. Pass frequencies each side of a band b. Stop frequencies each side of a band c. Only allow one spot frequency through 349) A low pass filter for a high frequency transmitter output would: a. Attenuate frequencies below 30 MHz b. Attenuate frequencies above 30 MHz c. Pass audio frequencies above 3 kHz 350) Installing a low pass filter between the transmitter and transmission line will: a. Ensure an SWR not exceeding 2:1 b. Permit higher frequency signals to pass to the antenna c. Permit lower frequency signals to pass to the antenna 351) An active audio low-pass filter could be constructed using: a. A transformer and capacitors b. An operational amplifier, resistors and capacitors c. Electrolytic capacitors and resistors 352) The input impedance of an operational amplifier is generally a. Inductive b. Very low c. Very high 353) The voltage gain of an operational amplifier at low frequencies is: a. Very high but purposely reduced using circuit components b. Very low but purposely increased using circuit components c. Less than one 354) An operational amplifier connected as a filter always utilises: a. Positive feedback to reduce oscillation b. Negative feedback c. Random feedback 355) Unwanted signals from a radio transmitter which cause harmful interference to other users are known as: a. Reflected signals
b. Re-radiation signals c. Harmonic signals and spurious signals
Module Electrical Power (ATA 24) 1) Emergency lighting is switched on prior to
a) Take off b) Switching ground power off c) An emergency evacuation 2) An APU generation system a) does not have a CSD b) uses an identical CSD to the main engine CSD c) uses a different type of CSD to the main engine CSD 3) The CSD/IDG governor speed control screw a) cannot be adjusted b) adjusts the oil flow rate c) adjusts the generator frequency 4) The transistor voltage regulator operates with a) pulse control b) rheostat c) high voltage 5) A three-phase alternator with a single-phase output of 115 V will have a phase-to phase output of a) 0.707 x 115 V b) 1.414 x 115 V US c) 1.73 x 115 V 6) A multiple phase alternator with a single-phase output of 115 V will have a phase-to phase output of 230 V a) it varies b) true c) false 7) The output voltages of a three-phase alternator are separated by 120 degrees
