Electrical Measuring Instruments/ Troubleshooting Flashcards Preview

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Flashcards in Electrical Measuring Instruments/ Troubleshooting Deck (26)
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1
Q

Voltage, resistance and power all relate to:

A

The flow of current

2
Q

The definition of full-scale current

A

The amount of current that must flow through a meter coil to cause a full scale deflection

3
Q

Define: Meter sensitivity

A

Reciprocal value of [full scale current], represents total amount of resistance for each volt needed to provide full scale current

4
Q

The amount of current required to give a full deflection on a meter is dependent on

A

scale that the meter is set to

5
Q

A meter that requires 1 milliamp of current to provide full scale deflection requires ____ ohms or resistance

A

1,000 ohms

6
Q

The function of the meter sensitivity resistance

A

Limits the current through the meter to the [full scale current]

7
Q

The total resistance of a meter is termed

A

meter resistance

8
Q

If the range of current to be measured is greater than the full scale current of a meter, what is installed and how is it installed?

A

Shunt, installed in parallel

9
Q

Basic description of a shunt installed in parallel to a meter

A

A resistor which increases the amount of current the meter can measure

10
Q

The type of ohmmeter used to measure very low resistances such as magneto coils

A

shunt-type ohmeter

11
Q

The basic operation of a Megohmeter (megger)

A

Hand cranked generator allows the megger to produce several hundred volts

12
Q

Multimeter resolution reffers to

A

How small a measurement the meter can make

13
Q

Digital multimeters display the _____ of AC voltage waves

A

RMS values (equivalent DC value)

14
Q

2 things the continuity function on a multi-meter can be used to detect

A
  1. Distinguish good/bad fuses

2. Distinguish good/bad switches

15
Q

What is considered to be zero reference for voltage during troubleshooting ?

A

Ground

16
Q

When a voltmeter is placed across an open component in a series circuit, what the multimeter reads

A

Battery or applied voltage

17
Q

The 3 RULES to apply to troubleshooting circuits

A
  1. Make a measurement ONLY if you know what the good measurement will be
  2. Make as few measurements as possible
  3. Select the best tool for the job at hand
18
Q

The measuring device that does not require the circuit to be opened in order to take a current reading

A

Current probe

19
Q

Measuring voltage across an open component in a series circuit reads

A

Supply/source voltage

20
Q

Measuring voltage across all other components in a series circuit except the defective component reads

A

zero

21
Q

Measuring voltage across a shorted component in a series circuit reads

A

zero

22
Q

Measuring voltage across an all other components in a series circuit other than the shorted component reads

A

higher than normal voltage

23
Q

Measuring voltage across all branches of a parallel circuit in a short reads

A

zero

24
Q

Measuring voltage across all branches of a parallel circuit if one branch is open reads

A

Source/supply

25
Q

Measuring resistance across an open component reads

A

Infinite

26
Q

The first step in troubleshooting using an ohmeter

A

ISOLATE the component