3272-11 sys (1.15)

A reduction in field strength of a DC shunt motor driving a constant load will result in. reduced torque and increased speed. increased torque and speed. increased torque and reduced speed.

What are the 2 short prongs on an AC plug for?. Using AC current to pull on interlock circuit. To prevent arcing during plug connection / disconnection. To help plug location/fit.

A vibration contact voltage regulator consists of a shunt winding and a. current regulation coil in series. voltage regulating coil in parallel. voltage regulating coil in series.

What is the purpose of diode in a power GCR?. To allow flow in the event of failure of the relay. To speed up the operation. To prevent back-flow of current in the EMF coil.

Eddy currents are. caused by heating effect of the coil. caused by resistance of the coil. circulating currents.

The small pins in the power connector plug are. neutral. negative. positive.

When an overvolt is present on an AC generator system, the tripping circuit. trips at a set level. trips after a time delay inversely proportional to overvolt amplitude. trips after a time delay.

In an AC distribution system, the purpose of the synchronising bus-bar is to. provide a means of monitoring the load. provide interconnection between the generator load busbars. supply essential services.

Vibrating contact voltage regulator sensing coil is. in parallel with the field windings. across the generator output. in series with the field windings.

A current transformer connected across the neutral of a 3 phase generator is for. differential protection. load monitoring. phase sequence monitoring.

Zener diodes are for. voltage regulation. voltage stabilisation. rectification.

AC generator output indications are measured in. KW & KVAR. KW. KVA & KW.

Load shedding allows. more voltage to the busbar. less current to the busbar. more current to the busbar.

How may the output of a transistorised voltage regulator be described?. Variable AC. Pulse width modulated DC. Slightly variable DC.

In the event of complete AC generator failure in an AC split bus-bar generation system, how is power maintained to the essential AC bus-bar?. By power fed from static inverter only. By power fed from a battery supplied static inverter. By power fed from a hot battery bus-bar only.

Which components within a generator control unit connects the output of the field power supply to the generator exciter?. Generator control relay. Generator line contactor. Generator power pilot relay.

In what units are static inverters rated?. kVAR. kVA. kW.

In a generator system, a stability winding is used. to control output current. in series with the field to prevent oscillations. to prevent voltage overshoot.

On engine shutdown, what prevents GCR being tripped?. Under-current. Under-frequency. Under-volt.

How is real and reactive load sharing achieved in an AC parallel generator system?. Real load by control of the constant speed drives, reactive load by adjustment of generator fields. Real load by control of generator fields, Reactive loads by adjustment of the constant speed drives. Real and reactive loads by control of the constant speed drives only. Output voltage is controlled by adjustment of generator fields.

Other than when there is a fault in an aircraft battery or its charging system, when is the charger switched off automatically?. When there is a failure of one alternator in a split-bus bar system. When the battery is used for excessively high discharge currents such as in starting. When the alternators are fully loaded.

The trimmer resister in a carbon pile volts regulator is. in parallel with the generator volts coil. in series with the generator field. in series with the generator volts coil.

When a field relay trips the generator off-line, it can be reset. after the fault has been cleared. on the ground only. by cycling the generator switch.

In a paralleled AC generator system both A phases must be in synchronisation and. CBA must equal ABC. phase rotation does not matter. CBA must equal CBA.

When loads are shed from a busbar automatically. bus bar voltage rises. bus bar current rises. bus bar current decreases.

What controls output from the generator?. BPCU. ELCU. GCU.

Specific Gravity in a lead acid battery should give an indication of. charge. electrolyte temperature. electrolyte level.

During normal engine shut-down, the generator. breaker and control relay are both tripped. control relay is tripped only. breaker is tripped only.

The generator warning light will come on when. voltage is too high. voltage is above battery voltage. voltage is below battery voltage.

When replacing a current transformer. it can only be fitted one way round. it can be fitted any way round. voltage/current selection must be made prior to fitting.

The economy coil on a relay. reduces current required to hold closed. reduces current required to close. makes it cheaper to make.

What is the function of the generator control relay?. Bring the generator on-line. Connect the generator to the busbar. Control output voltage.

The current consumed by a DC starter motor will. decrease as the engine speed increases. remain constant. increase as the engine speed increases.

A neutralising agent for sulphuric acid is. sodium bicarbonate. citric acid. borax powder.

In a split bus power distribution system. each generator supplies its own bus and distribution system in normal operation. power is split between 115V AC and 28V DC. generators are paralleled on connection to the tie bus.

Flashing a generator field. restores magnetism. increases resistance. decreases resistance.

When checking SG of electrolyte of lead acid battery, what should be taken into account?. Battery charge. Electrolyte temperature. Ambient temperature.

How do you check condition of Ni-Cad battery in situ?. By voltmeter in the cockpit when battery is off load. By voltmeter connected to the battery terminal. By voltmeter in the cockpit, when battery is on load.

The reactive load circuit in a multi-engined AC generator system. modifies generator field excitation current. modifies generator field excitation voltage. modifies generator drive speed.

A vibrating type voltage regulator uses a volts coil. in parallel with the generator output. in series with the generator output. in series with the current coil.

The purpose of the economy contacts in a relay is to. reduce the current required to hold the contacts closed. close the auxiliary contacts before the main contacts. prevent contact pitting and burning.

A vibrating contact voltage regulator has. a volts coil in parallel with the points. a resistor in series with the points. a resister in parallel with the points.

Brush bedding-in on a starter generator can be carried out. when 80 percent of the brush area has been previously bedded in, on the bench. only off the aircraft. during flight.

What would be the cause of a low electrolyte level in a nicad battery?. Evaporation. Over charging current. Undercharging current.

An AC generator connected to a CSD requires. no voltage regulator as the CSD will control the voltage. no voltage regulator as the CSD will control generator frequency. a separate voltage regulator.

If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed?. Apply sodium bicarbonate solution to the affected area followed by a water rinse. Rinse the affected area thoroughly with clean water. Apply boric acid solution to the affected area followed by a water rinse.

Which statement regarding the hydrometer reading of a lead-acid storage battery electrolyte is true?. The hydrometer reading will give a true indication of the capacity of the battery regardless of the electrolyte temperature. The hydrometer reading does not require a temperature correction if the electrolyte temperature is 60°F. A specific gravity correction should be subtracted from the hydrometer reading if the electrolyte temperature is above 20°C.

An increase in the speed of a DC generator will cause the voltage to rise with the following resultant action in the voltage regulator: The volts coil to exert less pull thus increasing the resistance of the carbon pile. The volts coil to exert more pull thus increasing the current in the generator field. The volts coil to increase its magnetic field thus decreasing the field excitation.

The equalizing coils on voltage regulators will. have current passing through them from the higher loaded generator to the lower. have current passing through them only when the generators are not paralleled. be connected to each other when the generators are paralleled.

A fully charged lead-acid battery will not freeze until extremely low temperatures are reached because. the acid is in the plates, thereby increasing the specific gravity of the solution. increased internal resistance generates sufficient heat to prevent freezing. most of the acid is in the solution.

What determines the amount of current which will flow through a battery while it is being charged by a constant voltage source?. The ampere-hour capacity of the battery. The total plate area of the battery. The state-of-charge of the battery.

The method used to rapidly charge a nickel-cadmium battery utilizes. constant current and varying voltage. constant voltage and varying current. constant current and constant voltage.

The presence of small amounts of potassium carbonate deposits on the top of nickel-cadmium battery cells that have been in service for time is an indication of. excessive gassing. normal operation. excessive plate sulphation.

The servicing and charging of nickel-cadmium and lead-acid batteries together in the same service area is likely to result in. normal battery service life. increased explosion and/or fire hazard. contamination of both types of batteries.

If the current drawn from No.1 generator of a twin generator DC system is less than that drawn from No.2 generator, the current in the No.2 generator equalizing coil will flow. in the same direction as the current flow in the voltage coil, reducing the output of No.2 generator. in the opposite direction to the current flow in the voltage coil, reducing the output of No.2 generator. in the same direction as the current flow in the voltage coil, increasing the output of No.2 generator.

On a C.S. driven generator, operation of the Disconnect Solenoid will disconnect the generator drive and. it can only be reset when all loads are switched off. it will automatically reset itself when the fault is rectified. resetting can only be carried out on the ground.

In a constant frequency AC system, real load sharing is achieved by regulating the. voltage regulator. generator drive torque. generator speed.

A constant speed drive unit has a warning light indication. for low speed. for low oil pressure. for when it is disconnected from the generator.

The electrolyte of a nickel-cadmium battery is the lowest when the battery is. being charged. in a discharged condition. under load condition.

Nickel-cadmium batteries which are stored for a long period of time will show a low fluid level because the. fluid level was not periodically replenished. fluid evaporates through vents. electrolyte becomes absorbed in the plates.

The purpose of 'field flashing' is to. change the polarity of residual magnetism in a field winding. test the insulation resistance of a field winding with a 1000V supply. measure the residual magnetism in a field winding 24 hours after the field supply is removed.

How can the state-of-charge of a nickel-cadmium battery be determined?. By measuring discharge. By the level of the electrolyte. By measuring the specific gravity of the electrolyt.

What may result if water is added to a nickel-cadmium battery when it is not fully charged?. No adverse results since water may be added anytime. The cell temperature will run too low for proper output. Excessive spewing will occur during the charging cycle.

In nickel-cadmium batteries, a rise in cell temperature. causes an increase in internal resistance. causes a decrease in internal resistance. increases cell voltage.

When a charging current is applied to a nickel-cadmium battery, the cells emit gas only. if they are defective. when the electrolyte level is low. toward the end of the charging cycle.

The equalising coil in the carbon pile regulator. is connected in series with the carbon pile. becomes inoperative when the undervolt relay energises. modifies the effect of the voltage sensing coil.

In a constant frequency AC system, reactive load sharing is achieved by regulating the. voltage regulator. generator drive torque. generator speed.

Under-frequency in an AC supply would cause. overspeeding of AC motors. overheating of inductive devices. overvoltage of capacitive devices.

The electrolyte in a lead-acid battery contains. sulphuric acid. nitric acid. hydrochloric acid.

In the procedure to be followed after spillage of battery acid, neutralizing may be carried out. by washing with distilled water. by applying a coating of petroleum jelly. with a dilute solution of sodium bicarbonate.

Frequency (Hz) is the number of cycles per. minute. second. revolution.

The three voltages of a three phase generator are. 90 degrees apart. 120 degrees apart. 180 degrees apart.

To restore the level of electrolyte which has been lost due to normal gassing during battery charging. sulphuric acid must be added. distilled water must be added. electrolyte of the same specific gravity as that contained in the battery must be added.

A 12 volt lead-acid battery. has 24 cells. has 6 cells. has 12 cells.

The active component of an A.C. circuit is 4 amps and the reactive is 3 amps. Ammeter reading will be. 5 amps. 7 amps. 3.4 amps.

In a delta connected generator. phase volts equals 1.73 line volts. line volts equals 1.73 phase volts. line volts equals phase volts.

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. strength of the magnetic field. number of conductors in the armature. speed at which the armature rotates.

As the generator load is increased (within its rated capacity), the voltage will. remain constant and the amperage output will increase. remain constant and the amperage output will decrease. decrease and the amperage output will increase.

When checking the specific gravity of the electrolyte in a battery. one cell only need be checked as the remainder will read the same. only the end cells need be checked as they contain the terminals. each cell should be checked as the readings may differ.

A lead-acid battery is considered to be fully charged when the. cells begin to gas freely. S.G. reaches 1.180. S.G. and voltage remain constant for specified period.

Which aircraft circuit would be most likely to use frequency wild 200V AC?. Hydraulic pump. Standby compass. Windscreen heating.

To prevent corrosion at the terminals of a lead-acid battery. copper connectors are used. the connectors may be painted. petroleum jelly may be applied to the connections.

Before taking S.G. readings of a lead-acid battery recently removed from an aircraft. the battery must be charged at the 10 hour rate for one hour. a period of 1 hour should have elapsed to allow the S.G. to stabilize. the electrolyte temperature must be noted.

The output of a DC generator is controlled by varying the. engine speed. field current. armature current.

A generator rated at 30 kVA power factor 0.8 has a maximum continuous power output of. 37.5 kW. 24 kW. 30 kW.

The specific gravity of the electrolyte in a lead-acid battery. remains constant with changes in the state of charge but is a useful guide to the amount of acid contained in the electrolyte. changes with the state of charge and is therefore a measure of the state of charge. remains substantially constant regardless of the state of charge and is not therefore a guide to the state of charge.

A battery which is assumed to be 100% efficient and to have a capacity of 60 ampere-hours at the 10 hour rate will deliver. 60 amps for 10 hours. 60 amps for 10 hours or 6 amps for 10 hours depending upon the rate of demand. 6 amps for 10 hours.

Two 12V 25 ampere batteries connected in series will produce. 12V with 25 ampere hour capacity. 12V with 50 ampere hour capacity. 24V with 25 ampere hour capacity.

As an installed battery becomes fully charged by the aircraft generator. the battery contactor isolates the battery from the generator. the battery voltage nears its nominal level so the charging current decreases. the generator voltage decreases to supply the steadily decreasing current.

On a DC shunt generator without a voltage regulator, if the load increases the generator output voltage will. decrease. increase. remain constant.