Electrical Measuring Instruments/ Troubleshooting

Question 1

Voltage, resistance and power all relate to:

Answer 1

The flow of current

Question 2

The definition of full-scale current

Answer 2

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

Question 3

Define: Meter sensitivity

Answer 3

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

Question 4

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

Answer 4

scale that the meter is set to

Question 5

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

Answer 5

1,000 ohms

Question 6

The function of the meter sensitivity resistance

Answer 6

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

Question 7

The total resistance of a meter is termed

Answer 7

meter resistance

Question 8

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?

Answer 8

Shunt, installed in parallel

Question 9

Basic description of a shunt installed in parallel to a meter

Answer 9

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

Question 10

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

Answer 10

shunt-type ohmeter

Question 11

The basic operation of a Megohmeter (megger)

Answer 11

Hand cranked generator allows the megger to produce several hundred volts

Question 12

Multimeter resolution reffers to

Answer 12

How small a measurement the meter can make

Question 13

Digital multimeters display the _____ of AC voltage waves

Answer 13

RMS values (equivalent DC value)

Question 14

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

Answer 14

1. Distinguish good/bad fuses

2. Distinguish good/bad switches

Question 15

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

Answer 15

Ground

Question 16

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

Answer 16

Battery or applied voltage

Question 17

The 3 RULES to apply to troubleshooting circuits

Answer 17

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

Question 18

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

Answer 18

Current probe

Question 19

Measuring voltage across an open component in a series circuit reads

Answer 19

Supply/source voltage

Question 20

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

Answer 20

zero

Question 21

Measuring voltage across a shorted component in a series circuit reads

Answer 21

zero

Question 22

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

Answer 22

higher than normal voltage

Question 23

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

Answer 23

zero

Question 24

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

Answer 24

Source/supply

Question 25

Measuring resistance across an open component reads

Answer 25

Infinite

Question 26

The first step in troubleshooting using an ohmeter

Answer 26

ISOLATE the component