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Question 1

4 electrical variables to be measured

Answer 1

Voltage, Current, Resistance, Power

Question 2

Advantages of analogue meters over digital

Answer 2

Easier to identify trends with the sweeping needle

Analogue meter doesn’t read ‘ghost’ voltages

Question 3

explain how the d’Arsonval meter works

Answer 3

A coil moves in proportion to a magnetic field created by the current you are measuring. The coil is connected to a needle which indicates on the analogue meter. A spring is attached to the needle and coil which brings it back to neutral when no current is applied

Question 4

Ammeter is connected to the test load in series, however internally the ammeter measures in parallel. T or F

Answer 4

True

Question 5

DC ammeters are not sensitive to current direction? T or F

Answer 5

False

Question 6

Shunts are connected in series or parallel to ammeters

Answer 6

Parallel

Question 7

How does a multi range ammeter differ to a normal ammeter

Answer 7

A multi range ammeter has multiple shunts with varying resistances. You can manually select the resistance you want so you can measure a range of current ratings without cooking the device

Question 8

For multi range ammeters you should always start at the lowest current range and work your way up to the required range to not blow up the machine. T or F

Answer 8

False

Question 8

Voltmeters should be connected in parallel. T or F

Answer 8

True

Question 9

What is the difference between a DC and AC meter?

Answer 9

An AC meter has a rectifier to convert AC power to DC for reading

Question 10

What current does a safety ohmmeter use

Answer 10

0.5mA

Question 11

How must you calibrate an Ohmmeter

Answer 11

Short the ohmmeter and then adjust the rheostat to get a ‘zero’ reading

Question 12

characteristics of a megohmmeter

Answer 12

A regular ohmmeter with a step up transformer to greatly increase voltage. low current

Question 13

What is the point of a Current Transformer

Answer 13

to measure current flow at levels which would otherwise be beyond the range of the meter

Question 14

Benefits of a clamp meter

Answer 14

you can conveniently measure the current of any wire by enclosing the clamp meter around the wire

Question 15

Generally, how often is a calibration required

Answer 15

1 year

Question 16

Logic probes are used for:

Answer 16

trouble shooting in logic circuits by indicating whether certain parts of the circuit are hi or low

Question 17

What is RMS

Answer 17

a way to compare DC to AC power. It is the point of an AC wave where the power output is the same as DC power. It is always 0.707x the AC peak

Question 18

Signal generators are used to;

Answer 18

test and align all types of transmitters and receivers

Question 19

What is an attenuator

Answer 19

Device that reduces the amplitude or power of a signal without distorting the waveform

Question 20

How does a time domain reflectometer measure where along the cable the error is?

Answer 20

the time taken for a signal to reach the end of a known length of cable is a known value. When a signal is received in a shorter amount of time, the speed of light and time to receive this signal is used to figure out how far away from the measurement the error in cable is.

Question 21

Pitot static testers;

Answer 21

consists of applying pressure into the pitot tubes at a controlled rate to check whether the pitot tubes are measuring and reading data correctly

Question 22

Turbine temperature tester works by

Answer 22

applying a temperature to the thermocouples to ensure they are reading data correctly

Question 23

Fuel quantity indication test sets work by

Answer 23

creating a fake capacitance signal on fuel sensing probes

Question 24

Why should you ensure Fuel quantity indication test sets are grounded

Answer 24

fuel and sparks do not mix

Question 25

Loop resistance testers analyses circuits of cables by;

Answer 25

measuring resistance at two locations within a cable loop to check for corrosion

Question 26

Circuit tests normally include

Answer 26

Bonding testing Continuity testing Insulation resistance testing Functional testing

Question 27

If arcing is detected you should

Answer 27

check bonding straps for corrosion

Question 28

How to test a bonding meter

Answer 28

Short the three prongs on both probes to obtain a zero reading Short two prongs of the double prong probe to obtain full deflection

Question 29

For general electrical bonding, what is the max lead resistance

Answer 29

0.1 Ohms

Question 30

Why should you use copper terminations on copper wire and aluminium terminations on aluminium wire?

Answer 30

to prevent dissimilar metal corrosion

Question 31

What class crimping tools, lugs and splices should not be used on aircraft

Answer 31

Class 2

Question 31

How do hand crimping tools prevent half crimps

Answer 31

Most have a self locking ratchet which prevents the tool from opening until the crimp is complete

Question 32

Order of colour determining wire gauge sizes

Answer 32

Yellow (smallest), Red, Blue (largest)

Question 33

What is the point of the abrasive compound inside an aluminium wire termination

Answer 33

during crimping, the compound releases and cleans the oxide film on the aluminium to avoid corrosion

Question 34

What should you inspect a crimped termination for?

Answer 34

Crimp indent centred on the terminal lug barrel Indent in line with the barrel Terminal lug not cracked Terminal lug insulation not cracked Insulation grip crimped

Question 35

What are splices used for

Answer 35

When a wire splits in the middle and needs to be reconnected

Question 36

Standard practices for splicing

Answer 36

splices must be visable for future inspection on bundles of wires requiring multiple splices, space the splices out to ensure bundle size doesn't increase usually only one splice per wire should not be used within 12in of termination

Question 37

What is the max bend radius of a coax cable

Answer 37

6 times the diameter of the cable

Question 38

Max number of wires in a bundle

Answer 38

75 or 5cm diameter

Question 38

Max distance between cable identifiers

Answer 38

15in

Question 38

Max bend radius of a regular cable, supported and unsupported

Answer 38

10x diameter unsupported 3x diameter supported

Question 39

What should be installed when a wire passes through a bulkhead or wall cutout with less than 1cm clearance

Answer 39

a gommet around the wall

Question 40

Wires must be be spaced as far away as possible from plumbing lines. T or F

Answer 40

True

Question 41

The purpose of flux is to

Answer 41

remove oxidation during soldering

Question 41

Hard solders are used for

Answer 41

Situations where greater mechanical strength or exposure to higher temps is required (e.g. Thermocouples)

Question 42

Flux core solder is

Answer 42

A solder wire with a channel of rosin flux inside, providing a convenient and controlled flux application

Question 43

Heat sinks are used for

Answer 43

absorbing unwanted conducted heat before it reaches the hear sensitive circuitry around the joint you're soldering

Question 44

How long do you have to clean flux residue post soldering

Answer 44

1 hour

Question 45

What is the most efficient soldering iron temp for general use

Answer 45

240-270