MULTIMETERS

Question 1

What are the two basic types of multimeters?

Answer 1

Analog and digital

Question 2

Describe the basic operating principle of an analog multimeter?

Answer 2

The multimeter takes the energy from the circuit under test and converts that energy into a magnetic field and the magnetic field is determine by the amount of variable current in the circuit

Question 3

Mulimeters are capable of measuring what three electrical characteristics?

Answer 3

Voltage, Ampere and Resistance.

Question 4

What are two disadvantages of an analog multimeter

Answer 4

Fragile and interpretation

Question 5

What term is used to describe the calibrated resistance that is placed in series with a multimeters leads in order extend the useful range of a multimeter when measuring voltage?

Answer 5

V” Multiplier

Question 6

What term is used to describe the calibrated resistance that is placed in parallel with a multimeters leads in order to extend the useful range of a multimeter when measuring current?

Answer 6

Shunt.

Question 7

What are two advantages of a digital multimeter?

Answer 7

No interpretation errors and autorange

Question 8

Prior to making resistance measurements in an electrical circuit, the power should be turned

Answer 8

___off______.

Question 9

What should be checked prior to using a multimeter

Answer 9

• Check calibration.
• Inspect, check for damages and condition.
• Setup, set the right function range and connections.
• Choose scale.
• Zero meter.
• Zero ohm adjustment when making resistance measurements

Question 10

How often does a multimeter require calibration?

Answer 10

Requires a annual calibration.

Question 11

1What is the source of power/current when making resistance measurements?

Answer 11

The battery in multimeter.

Question 12

The operation of an analog multimeter is based upon what principle?

Answer 12

Base on permanent mag field and electromagnetic mag field produced from the current flowing in the circuit.

Question 13

If you are not sure of the value you are measuring, what setting/range should you start with?

Answer 13

Start with highest range first to avoid any damage in multimeter

Question 14

List the steps for properly setting up your multimeter for measuring AC.

Answer 14

Select the AC function in multimeter

Question 15

Describe how current is measured

Answer 15

Current is measured with an ammeter connected in the current path by braking the circuit and inserting the meter in series, the positive side or lead should be connected towards the positive voltage source, the meter should not affect the current however the internal resistance in the meter may have some effect in the reading but is significantly small.

Question 16

Describe how voltage is measured

Answer 16

Voltage is measured with a Voltmeter, polarity must be correct when placing the probes across any component before making any measurements red lead should be connected to positive jack and black lead should be connected in the negative jack of voltmeter same when taking measurements on the components the polarity should match the component, this will prevent a incorrect reading or damage

Question 17

Describe how resistance is measured.

Answer 17

Resistance is measured with the ohmmeter, first the leads should be connected in the correct jacks of ohmmeter, the meter must be adjusted before use and should be zeroed before each use, power in the circuit must be turn off, then a constant current power by the battery meter is passed through the resistance that’s being tested and the ohmmeter measure the voltage across the resistance.

Question 18

How much resistance is need it for continuity test

Answer 18

15 ohms

Question 19

Factor to consider making a measurement

Answer 19

Circuit on or off, E is measured in a parallel. I and R are measured in series

Question 20

computing funtions for DMM

Answer 20

Input, decision, memory, output,

logic AND OR NOT

Question 21

What must be known prior making measurements with MM

Answer 21

What values will be measuring
MM specifications
Manual ranging, limit, max and extended and minimum readings

Question 22

Voltage and current must be measured with power

Answer 22

ON

Question 23

Resistance and continuity must be measured with power

Answer 23

OFF

Question 24

DMM types

Answer 24

Ranging and autoranging

Question 25

DMM advantages

Answer 25

No intepretation errors
easy set up
easy operation
Rugged

Question 26

DMM tips for leads

Answer 26

Contact, scratch and press

Question 27

Basic analog MM parts

Answer 27

Display, funtion,connectors, test leads

Question 28

Analog MM caracteristics

Answer 28

Infinitely variables scale
moving parts
Basic operation interaction of two magnetic fields

Question 29

Analog MM funtion

Answer 29

A mag field is produced by a MM permanent magnet and a mag filed produced from “I” flowing in the circuit under test variables of electromagnetic

Question 30

Disadvantages of analog MM

Answer 30

Fragile
interpretation
errors
required effort

Question 31

FAA 4 checks

Answer 31

Visual
functional
operational
Bench

Question 32

MM set up

Answer 32

Inspect
select function/range
connect probes
prepare circuit under test
make measurements

Question 33

Requirements for a MM

Answer 33

Capabilities
consistancy
reliability

Question 34

Rheostat

Answer 34

Has 2 connection points examples light dimmer, panel, radios Rheostat drops voltage

Question 35

Potentiometer

Answer 35

Has 3 connections example a volumen control in a radio Potentiometer divides voltage