Electricity Self Test

Question 1

This term describes a noisy, uncontrollable arc that flares from side to side.

a) arc voltage
b) arc blow
c) inductance
d) resiststance

Answer 1

b) arc blow

Question 2

This term describes the influence excerted by a magnetic field on neighbouring bodies without physical contact.

a) voltage
b) amperage
c) frequency
d) inductance

Answer 2

d) inductance

Question 3

This is the fundamental unit of electricity that moves through a conductor when current is flowing.

a) resistor
b) electrons
c) conductors
d) rectifiers

Answer 3

b) electrons

Question 4

Which term describes the NEMA rating of a welding machine?

a) duty cycle
b) reverse polarity
c) arc voltage
d) amperage

Answer 4

a) duty cycle

Question 5

Electrode positive means:

a) straight polarity
b) reverse polarity
c) AC transformer
d) alternating current

Answer 5

b) reverse polarity

Question 6

Electrons have a ________ charge

a) neutral
b) 12 volt
c) positive
d) negative

Answer 6

d) negative

Question 7

Which term measures the strength of a current of electricity?

a) amperage
b) voltage
c) electron
d) inductance

Answer 7

a) amperage

Question 8

What term describes a medium that provides a electrical path for current to flow through?

a) cycle
b) circuit
c) conductor
d) core

Answer 8

b) circuit

Question 9

The electron flow theory states that electrons move from ______

a) positive to negative
b) negative to positive

Answer 9

a) positive to negative

Question 10

The tern that descibes a material that can stop current flow through itself

a) inductor
b) inverter
c) conductor
d) insulator

Answer 10

d) insulator

Question 11

Which term describes the voltage output of the machine during welding

a) arc rectification
b) arc blow
c) arc voltage
d) inductance

Answer 11

c) arc voltage

Question 12

When current flows thorough a coil wrapped around an iron core, what is created?

a) a magnetic field
b) reverse polarity
c) transformer rectifier
d) duty cycle

Answer 12

a) a magnetic field

Question 13

This device in a welding machine is designed to have a certain number of turns of wire.

a) circuit
b) core
c) coil
d) cycle

Answer 13

c) coil

Question 14

The main function of this device is to change AC to DC

a) resistor
b) rectifier
c) relay
d) reactor

Answer 14

b) rectifier

Question 15

Electrode negative is

a) straight polarity
b) reverse polarity
c) ac transformer
d) alternating current

Answer 15

a) straight polarity

Question 16

This current flows in one direction only and has either a positive or negative value

a) direct current
b) alternating current
c) open circuit voltage
d) arc voltage

Answer 16

a) direct current

Question 17

Which term describes a piece of equipment used to create electricity of sufficient volume for welding

a) inductor
b) resistor
c) transformer
d) generator

Answer 17

d) generator

Question 18

Which is a graphical illustration that plots the relationship between voltage and amperage output of a welding power source?

a) open circuit
b) volt-amp curve
c) elecrtomtove force
d) duty cycle

Answer 18

b) volt amp curve

Question 19

When no current is flowing in the circuit but the machine is turned you can measure the

a) open circuit voltage
b) volt amp curve
c) alternating current
d) volt amp curve

Answer 19

a) open circuit voltage

Question 20

The speed at which AC changes direction is called the

a) voltage
b) amperage
c) frequency
d) resistance

Answer 20

c) frequency

Question 21

This term describes the property of an electrical conductor that opposes the flow of current

a) resistance
b) inductance
c) voltage
d) amperage

Answer 21

d) amperage

Question 22

In welding this term describes what is created when there is enough amperage and voltage to overcome the natural resistance to the flow of the electricity

a) amp
b) volt
c) cycle
d) arc

Answer 22

d) arc

Question 23

List three advantages of three phase system over single phase systems

Answer 23

a) constant power
b) smaller equipment
c) more efficient

Question 24

What phase of power supplies most industrial applications

a) single phase
b) tow phase
c) three phase
d) four phase

Answer 24

c) three phase

Question 25

This welding machine transforms AC to DC a) line transformer b) transformer rectifier c) DC generator d) AC transformer

Answer 25

b) transformer rectifier

Question 26

This term describes one complete revolution of the AC alternator a) circuit b) core c) coil d) cycle

Answer 26

d) cycle

Question 27

What happens when mechanical energy is applied to a conductor and it moves across a magnetic lines of force in a magnetic field a) Magnetism is generated b) Electrical current is generated c) single phase power is generated d) three phase power is generated

Answer 27

b) electrical current is generated

Question 28

These machines convert high voltage low amperage to low voltage high amperage any the use of a primary and secondary coil a) AC transformer b) AC generator c) DC generator d) AC alternator

Answer 28

d) AC alternator

Question 29

What does EMF stand for? a) electron movement force b) elementary motor force c) electromotive force d) electromotive factor

Answer 29

c) electromotive force

Question 30

Which term describes the typical sound of a AC transformer welding machine? a) turbine whine b) high pitched scream c) buzz box d) whisper quiet

Answer 30

c) buzz box

Question 31

The type of welding machine that is capable of changing DC to high frequency AC a) AC generator b) DC rectifier c) DC generator d) inverter

Answer 31

d) inverter

Question 32

What is the function of the secondary winding on a transformer welder? a) to induce high frequency current b) to serve as a back up in case the primary winding fails c) to step down the voltage d) to step up the amperage

Answer 32

c) to step down the voltage

Question 33

One advantage of an AC transformer welder is freedom from a) undercut b) arc blow c) porosity d) slag inclusion

Answer 33

b) arc blow

Question 34

What is the purpose of a silicon controlled rectifier a) to change AC to DC b) to change single phase to three phase c) to increase the welding speed on aluminum d) to change DC to AC

Answer 34

a) to change AC to DC

Question 35

What is one advantage to an AC-DC transformer rectifier welding machine? a) arc blow is not a problem b) the purchase price is lower than for a transformer c) you have choice of polarity d) it does not have to be kept clean or cool

Answer 35

c) you have a choice of polarity

Question 36

A DC motor generator produces what type of welding current a) rectifies b) AC c) DC d) high frequency

Answer 36

c) DC